Home > Open Discussions > Domestics > heat issue

heat issue

  1. Please fill out the following to ask a question.

    MAKE: Dodge
    MODEL:Ram 15004x4
    ENGINE:5.2 v-8
    DESCRIBE ISSUE....ok first is temp gauge is barely coming above roughly the 145 to 150 degree mark even though i just put in a new thermostat that is supposed to be a 195 degree one if i crank the blower fan all the way on i get luke warm at best if however i drop it one click its warmer but still not exactly making you want to take your coat off warm i am wondering if possibly the heater core may need to be flushed out?water pump looks to have been replaced not long ago i have only had the truck maybe 6 months also if it sits just idle the air coming out of vents does cool down not sure 100% what is going on
  2. If the engine won't come up to temperature, there is little point to chase other things in the heater system; like core, valve, or blend-door. I can't think of anything that will prevent the engine from heating up properly except the t-stat or some mis-routing of the coolant lines. Even a problem with the coolant line routing is a real stretch, but coolant systems have become more complicated in modern times, so it may be a possibility. The t-stat is what I would look at, even though it is new...

    Hmm... I just peeked at Rockauto listings for that t-stat. Some (the cheaper ones) specify "reversed poppet". What do you suppose that means? OP, what one did you put in?
  3. thing is i had this going on before replacing the thermostat all the hoses are proper as i had a mechanic friend do the job for me as i am not fond of working outside in the freezing cold lol
  4. Well, I peeked at that part on the O'Reilly link, it lists 1000 Dodge vehicles it is compatible with and I'm not seeing the '98 Ram 1500 5.2l as being one of them. I'm still wondering why some of them are called "reverse poppet" on the RA site.
  5. it says right on page when i open it fits 1998 dodge ram 1500 and the vehicle i have put in isthe 98 ram 1500 5.2 so it shows it fits other than that i have no idea what the "reverse poppet" means or why they call it that
  6. well upon clicking on more info on rock auto it lists this :
    Gates makes several types of thermostats in order to provide the same design as specified by car manufacturers:

    - The reverse poppet thermostat opens against the flow of coolant from the water pump. The coolant, under water pump pressure, is used to help the reverse poppet thermostat stay closed when cool to reduce leakage. This type is engineered with a self-cleaning, self-aligning stainless steel valve

    - The offset thermostat with jiggle pin valves is equipped with a special valve in the flange, which allows trapped air in the system to escape and permits the venting of air from the system when filling it with coolant
  7. i am also assuming that the temp gauge is registering properly i might take and get the whole system flushed it puts enough out to take the edge off as long as i keep the rpm up it will at least defrost the windshield and its still warmer than not working at all but just not like i feel it should be
  8. Yeah, that link says "98 Dodge 1500 Ram", but it doesn't say which of the (three) engines. Go down that page to the "compatibility" listing. I didn't see your specific config, with 5.2l listed, but may have missed it since there are 1000 in the list.

    Understand, I'm not certain that t-stat is wrong, but I know of no other things that will cause the engine to run too cold except a t-stat that won't close properly or piping that has, somehow, been routed to bypass the t-stat. Bad pump/cap/radiator, plugged passages anywhere, air in the system won't do it; all those make an engine run too hot. Have you confirmed engine temp with a separate thermometer? Dash gauges are often not accurate (same for IR guns) and it is vital that we know whether we are chasing an engine heating problem, or a problem with how the heating system uses the engine heat.
  9. i haven't had anything else checked but was told that it could be the heater core partially blocked as to why if i reduce fan speed it gets warmer heat vs with fan on high it only gets lukewarm at best everything else looks to be fine all hoses are run the way they should as top radiator hose runs direct to t-stat i will have to see if i can get the engine temp checked better i don't have but basic tools myself to do most of the basics to my vehicles ie: brakes oil stuff like that i am looking for ideas as to what could be the issue its not over heating for sure just doesn't seem to come upto temp truck runs great other than that
  10. I recommend the "too hot to hold" test. Drive vehicle until gauge is as high as it is going to get. Turn blower fan off. Rev engine 2000 RPM for about 30 secs. At idle, put your bare hand on hose that is engine-to-heater (not heater-to-engine). Try them both is you can't tell the difference. One of them should be too hot to hold for more than a couple seconds. This test bypasses possible problems with inaccurate gauge or partially blocked heater core.
  11. i will try that and see what i figure out i may have to zip to town in a bit so be good chance to do that
  12. ok tried the "too hot to hold" test and surprisingly neither hose was more than warm at best could it be maybe the water pump is going or?? i was expecting one to be blazing hot the other maybe cool but nope
  13. As to the operating temperature, 140* is very hot to the human touch. Can you confirm the actual coolant temperature with a calibrated melt stick, an infrared heat gun, or the like?

    Is this an all-original truck, or a made-up one? Somebody on this forum was tinkering with some made-up trucks and I thought they were Dodges. If there's been an engine swap or engine parts swap, funny things can happen. Such as: If an engine was built with accessories driven by vee belts, water pump runs same rotation as crankshaft. Engine built for serpentine belt, water pump is driven off the back side of the serp belt with runs it in opposite rotation. Wrong belt drive, wrong water pump, flow could be wrong and not supply the heater core. In cold weather, the engine might not overheat.

    Or simply, is the engine cooling system clogged? Is a heater hose fitting clogged with rust?
  14. So, maybe your gauge is accurate and engine temp is actually low. I know, its a new t-stat so "it can't be that". Next easy test without taking anything apart would be to pinch upper radiator hose so that all heat will stay in the engine.
    Drive vehicle until gauge is as high as it is going to get. Turn blower fan to low speed. Pinch off upper radiator hose and let idle while watching temp gauge and feeling heater output. If temp rises to normal range and heater starts to work good, a t-stat problem is indicated. Do not let engine get too hot before un-pinching radiator hose.
    Are you sure that cooling system is 100% full? Sometimes the "coolant bottle" has a bathtub ring and fools you into thinking coolant is full when it's not.
  15. yes coolant is full and vehicle is stock engine wise and jd i would think 140 is good as well but it has a 195 t-stat and anyone else i talk to that has one of these trucks says their temp gauge runs about mid way with great heat i took pic after long road trip today of temp gauge and that seems to be the best it gets
  16. We are sure wandering in the weeds here! Stick a cheap cooking thermometer into the coolant and let's get past any wonderment about what the coolant temp is.
  17. I'll have to get one when I go out
  18. Is the plan to "remove radiator cap, put thermometer into coolant"? Might be tough to get a good reading in cold weather with a radiator of this design. I think that truck uses a belt driven fan that pulls air thru the radiator, even if the fan clutch is "disengaged". So, I would expect a (hard to estimate) heat loss between coolant entry point and contact with the thermometer.
  19. yes it is run off the water pump by the serpentine belt i have not been able to get a thermometer yet and in order to get what heat i get i have to keep the rpm's up luckily its a 5 spd manual so i can run in 4th where i normally would 5th but even still i can't run the heater fan on full orit cools offmain things i have even seen cause it are weak water pump and heater core truck is somewhat a work in progress as i think it sat for 3 or 4 years before i bought it
  20. Well, pinching off the upper hose would only require some very basic equipment. If you had two wooden sticks and some wire, it could be done. Putting cardboard on front of the radiator would be another diagnostic route, but pinching the hose would be more definite.
  21. I went and bought a meat thermometer today and checked coolant it's getting to 110°F by that at radiator then dropped to like 80° not sure what is going on if I have rpm around 2k it blows ok heat
  22. I did the 30sec at like 2k rpm and checked with thermometer and it got to almost 130° at radiator then dropped but both heater lines were rather warm not overly hot but above warm
  23. The thermometer was immersed in the coolant?
  24. Yes I talked to my mechanic friend and he had a customer deal with same issue his was vaper lock
  25. "Yes", the thermometer was immersed in the coolant; or "yes", I talked to my mechanic?

    That "vapor lock" theory is full of, well... gas. There is always vapor in a cooling system. That's the whole point of pressure-caps on cooling systems, to raise the vapor pressure from the sea-level atmospheric 212F to something higher. Automotive coolant pumps are almost always down low enough that they are flooded with coolant as long as coolant level is anywhere near normal. I suspect your mechanic meant an "air lock" that can cause hot spots in the cooling system. But, that isn't your problem at all is it? You can't get it up to heat.

    I still am convinced that the only way you can over-cool is a bad t-stat or plumbing that has, somehow, bypassed the t-stat. Every other kind of problem causes over-heating.
  26. Yes the thermometer was fully in the coolant. And nothing has been bypassed in the cooling system the thermostat is right in with the upper radiator hose
  27. I am going to have to recommend my previous suggestion. Pinch upper radiator hose and see how the heater works when the engine temp gauge reaches midpoint.
  28. I will see if I can get what is needed to do that too but my mechanic found this out that these engines tend to get a pocket of trapped air by the thermostat neck as he talked to someone who had same issue I have and was throwing part after part at it until supposedly another shop found the problem was trapped air and had to drain the cooling system,fill like half way,let it run a while then slowly add more coolant this is just what I heard the guy tell him and he said it solved the issue for him sounds strange to me as well as I always thought with normal radiator that has cap on it you just had to burp it a little as heat line comes directly off water pump. I did one thing tonight when I stopped to help someone broke down is I held it at like 1500 rpm (, estimate as I have no tach in this truck but yet and auto trans does) and it got nice and warm in truck but under normal circumstances it doesn't.
    I'll see if I can find a couple small boards to go either side of upper hose and clamp it and see if it makes any difference
  29. Ok took today and swapped hoses at heater core to reverse flow through to possibly purge and minor blockage and stuff a large sheet of cardboard in front of radiator and at idle still get squat for heat if I bring rpm up around 3,000 it gets warmer coolant temp still not above 150° and gauge still not even close to mid way
  30. Are you accepting that the engine is not getting up to normal temp? With that condition the heater can never work properly and you are just wasting time fussing with it and its hoses. If you don't believe the temp is way low, say so and I will butt-out; any further discussion is a waste of my time.

    If you do believe that engine temp is low, then put the clamp on the upper hose that Dan suggested. That will act as a manual t-stat and probably heat the engine up and confirm that this is simply a matter of a bad t-stat.
  31. I think it's fairly obvious it's not getting up to temp when I run it at high rpm it throws ok heat I figured the cardboard blocking radiator would act in similar fassion to closing off upper radiator hose as my heater line is not off the t-stat housing but the water pump
  32. Pinching the hose is going to be way more effective, I believe.

    I'm assuming you don't have an official mechanics hose pinching tool, and not even some kind of wide wood-working clamp, so I suggested something more low-tech. Two sticks, pipes, bars, whatever...wrap string, rope, wire, zip-tie around both at one end, then put the hose between the sticks and squeeze like grandma's nutcracker. Then, fasten the other ends together. Don't get the contraption in the fan.
  33. Yes my guy is going to do that tomorrow and see what happens it's really my only option I can see at this point as cardboard isn't making much difference
  34. Two sticks about 6" long, and two pieces of all-thread about 6" long. Search online for "bearing separator" and the resulting pictures will explain what to make.
  35. I may be trying to hit home a nail that has already been driven. I have to agree, 100%, completely with Bill's comment.

    SO, my $.02 is.

    If all suggestion in this thread still produce a no heat condition "IN THE TRUCK"

    Stop fussing and buy a new heater core.

    Why do I say this? I am a northern automotive technician and have had issues like this all my life. 99% of the time, even when you think the heater core is reversed flushed or whatever. The heater core is still blocked. No amount of flushing out the air lock/vapor lock whatever else term I can try to find in my french brain is going to change that.
  36. You just answered you own question.
  37. I am still a patient guy, sometimes not, but here is more proof. I was a technician for mopar for many years, have worked on zillions of ram's.

    There was a thread here that talked about how sometimes, ppl like us that give out free advice are seen as snobbish. I think I want to change that. But in the mean time, if ppl that post here don't follow advice, what else can us FREE techs do?

    Step 3 of following snapshot, read it carefully. If you don't find a solution, your not looking at the problem from a proper prospective. I love Sherlock holmes quotes, they fit MY logical thinking. As others here also. ;)

    ‘It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.’

    ‘Eliminate all other factors, and the one which remains must be the truth.’

    Screenshot (142).png
  38. I guess that was my rant of the end of day. My back is tired from snow, I am going to retire, watch some UFC fights to give me more courage to affront the next day of my challenge in life which is going back to work in my day job.

    @Oddone, I wish you all the luck, hope I didn't come on as condescending, and wish you will follow our advice to the upmost of your abilities. Also, happy new year to you.:):bat:
  39. Well we did the block the upper hose and made no difference what so ever the main issue seems to be that the engine itself is not coming up to temp.
  40. Also sitting idle for over 30min I checked the coolant temp at the radiator and was barely 90° so I know that obviously the thermostat will not open if the engine coolant temp is not high enough by just started a loss here I have looked at everything mentioned and tried what has worked before for me and nothing I do seems to make a difference hose clamped off and air through radiator blocked and still not coming up to temp
  41. On further note while out idleing the heater core let go and sprung a leak so going to change that out and go from there
  42. Are you saying that while idling for thirty minutes with the upper radiator hose clamped off, the temperature gauge never went higher than normal, and the heater temperature did not improve?

    The measurement at radiator, was that with the hose clamped off? If the hose was clamped off 100%, the radiator should have been stone cold.

    Your results maybe make sense if the hose was not truly clamped off.
  43. I checked after we unclamped but while clamped the gauge did not go any higher and heat did not improve at all
  44. But I have to replace the heater core tomorrow as it started leaking
  45. If you are taking the truck to "your guy", maybe he has a scanner that reads live data, and you could read information from the computer's sensor for engine coolant temperature. But, I assume he would have done that if he could.

    A new heater core will simplify any further diagnostics if heater core replacement doesn't increase heater performance to "good enough".
  46. What is the ambient temperature where this testing is being done? In my area, where "bitter cold" is 30F, no engine will keep from overheating if there is no flow through the radiator; but maybe the guys experienced with true cold can calibrate me better.

    Maybe some pictures of how you have that hose clamped would help.

    If you are taking it to anybody who does not have the capability to get OBD2 live-data, I think you are going to an iffy shop; I would be wary of any diagnosis given.
  47. I take it to a friend but I didn't get pics of clamp set up by and as of now truck is down waiting to replace heater core as it failed and lately ambient temperature here has been around 10°F or lower but I'm wondering as my heater core feed hose runs directly off water pump and not the thermostat housing but blocking upper hose had absolutely no affect on temp or heat. Once heater core is done will see if any improvement but as of now that's where I'm at
  48. This is what we used to clamp off hose IMG_20180108_151345.jpg
  49. Fuzzy pic, but looks like that is a setup that should get the job done. Ratchet clamp and two blocks of wood? On the upper RADIATOR hose? Hard to imagine that engine would stay cold just by fan blowing on engine block....but maybe...

    Maybe I will look for hose routing for that truck...1998 Ram pickup with 5.2 V8.
  50. [​IMG] Heater core gets hot coolant from the hose that attaches to that pipe to the left of the thermostat.
  51. Coolant returns to the engine through the hose that fastens to the pipe that sticks into the water pump.
  52. I am hoping that the heater core maybe the problem seeing as is let go during blocking the upper hose waiting on my guy to get it replaced
  53. Have you been watching this guy the whole time; are you sure he didn't try to "blow out" the heater core with compressed air or a garden hose? A heater core should not rupture from just the pressure of the water pump, no matter what you are doing with the hoses. As to the clamping of the upper hose, I have to suspect that light-weight type clamp wasn't adequate, or simply wasn't tightened enough. Pictures of the clamping as it was actually done is what I was looking for; I want to see how well that hose was squeezed flat.

    Nickb2, oh frigid guru, what do you think is the probability that an engine can cool OK forever with no coolant flowing through the radiator?
  54. Yes I was watching I did not take pics of when it was clamped I have pics of what we used I trust this guy 1000% I used to work for him and he is a straight shooter nothing other than clamping and reversing the heater lines was done IMG_20180108_151345.jpg
  55. Have run an engine for weeks without any radiator, just the two hoses connected with a union made of muffler tubing. But that is, mind you @ -55c temps. That was also because the rad was a complete loss, and the radiator was going to take close to a month to get in that remote region of this planet. The big gaping hole the now gone rad was more than enough to cool down that engine while driving, if thats what you can call driving in Nunavut or Innu nation territory. Trucks and car are more like skiddoos on wheels. Don't need a radiator, the snow build up while driving in engine bay is quite enough. Don't let it idle too long though. ;) How did we check coolant level, we simply didn't and didn't care. Could hear the air gurgling in the truck, would burp it once in a while by loosing a clamp, when we had no heat in the cab, but then again, we couldn't idle it to long to stay warm, but with our snow suits and eskimo gloves on, we just laughed and drank beer and waited for the engine to die, which it never did. When the radiator was finally arrived and installed, the engine was no worse for wear.

    In the meantime, we used a t-union for flushing with a screw on cap for hose adapter to fill it with a 70-30 coolant solution. That we attached to a heater hose, we made sure we had long enough to get the hose high enough and let gravity do the rest. How that for cannuck stupidness and can do attitude when nothing else is available but still need a work horse to work and drive and drink beer while doing both at same time.:eek:;):beer:

    But in the case of this thread, I think I will wait to see where this goes once the heater core is in. For some reason, I had a feeling it was no good, same reason it sprung a leak "all of a sudden"
  56. I gotta ask... if you idled that engine for a long period, would it start getting quite hot? I can certainly believe frigid air and snow blowing in through that missing rad opening could cool well enough. And, I'm guessing that truck engine wasn't pulling all that hard in those kind of weather conditions; it's kind of hard to maintain high speeds for extended periods, no matter how foolish the driver.

    OK, back to the topic. Yeah, let's wait to see what the OP finds after the heater core is replaced, since that has to be done anyway now.
  57. In "The case of The Radiatorless Truck", if the heater was working, it might be able to keep to engine cool under those conditions (low speeds, frigid temps). I have noticed that for some cars in cold weather, the electric radiator fan will never come on at an idle if the blower fan is cooling the heater core.
  58. Ok heater core finally done what a pain that was! It was severely plugged believe it or not with chunks of permatex from when previous owner did the water pump. However now it's coming up to almost 210°F when sitting idle but once moving drops way down even with radiator still having cardboard in front of it. At idle heat is great but drops a lot once moving it's better than it was but still not 100%
  59. Only thing he missed was the Cable to switch from defrost to floor to pannel he's going to fix that this week as it's stuck on defrost so my feet are still chilly lol
  60. Your latest description of symptoms strongly suggests that the problem is with the thermostat. Stuck open, opening too soon, not closing completely, whatever...it's letting too much engine heat get out to the radiator.

    There may be "chunks of Permatex" caught in T-stat preventing it from closing properly.
  61. That is my impression that t-stat is defective even though it's new that will be the next step
  62. This looks like real progress. I'm encouraged!
  63. Sat on side of Rd helping a motorist and gauge come up to 210°F and heat about cook you out but once moving down Rd it drops it's just really weird I have to see when my guy can swap t-stat out as it's new but suspect it maybe defective out of the box