Coolant in oil

big al

Hero Member
Joined
Aug 27, 2007
Messages
277
Likes
2
Points
18
#1
Make
Chevrolrt
Model
Impala
Year
2003
Miles
155000
Engine
3800
Famous gm 3800 intake gasket leaks. I want have them run a cleaner thru it for 250 miles, then change oil again. They dont want to remove heads so im hoping to find a cleaner that will help remove what i cant get to. Any suggestions
 
Joined
Mar 1, 2002
Messages
3,409
Likes
44
Points
48
Location
Kentucky
#2
Engine oil. Anything else may bust stuff loose over the course of 250 miles that would plug the pickup or filter. Plus, if the bearings fail, it's your fault, because with your cleaner in it, the vehicle is "still under your care" until the cleaner is removed. Not a gamble I would take on a car that I could not monitor constantly for oil lamp illumination characteristics at startup or high speed operation or hot idle in gear.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,565
Likes
137
Points
63
Location
St-Hyacinthe, Quebec, Canada
#6
Much less just wreak havoc on main journals and main caps.

I would suggest, plug coolant leak.

I am assuming that the intake gaskets flooded the crankcase oil with coolant. In that case. Just flush it out with cheap engine oil once the intake job is done.

Caps lock forthcoming.

DO NOT PUT ANY DETERGENT ADDITIVE IN THERE AT THIS POINT AS YOU WILL MOST LIKELY DESTROY THE BASE.

Caps off.

Buy recycled oil, I don't care. but do this two times just to see if the push rod engine starts to knock. If it doesn't knock, then after the second cheap oil change, should be back to normal.

So to re-camp, flush old chocolate milk oil with new cheap ass oil, then drive a few miles, such as 250 miles. 250 miles with a detergent in there will kill the mains.

A proper flush with a detergent when coolant enters the crank case is never that long. I do that just in my bay with car on lift and monitored at all times. This is what we call a 10 minute flush.

Anything other than that will cause a severe knock, push rod engine good for junk.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,565
Likes
137
Points
63
Location
St-Hyacinthe, Quebec, Canada
#7
You want a 10 minute crankcase flush, this is what I use, and yes, I am a professional tech. Liqui moly is good best I have used so far for symptoms like this, but expensive and only use it for high end engines. but I like the wynns engine treatment kit for low end engines such as your push rod 3.8l.

Bottle says 20 minutes, but i prefer to do two of these treatments to save main journal bearings from going south. https://www.wynns.eu/product/engine-flush/
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,565
Likes
137
Points
63
Location
St-Hyacinthe, Quebec, Canada
#8
Overkill for your gm product, but if you want to make sure, great product I use for german engines. Nothing no where near what you have. SO wynns should do, or STP for that matter.

https://www.amazon.in/Liqui-Moly-Engine-Oil-Flush/dp/B01HSAGL34

But from my experience, don't rinse with a detergent, just flush with regualer oil, cheap grade, then flush again and fill with a optimum oil. Should be ok, unless you drove forever with the coolant washing the mains. If that is the case, future knocker for sure no matter what you do.

Link for STP , Notice all are 10 min or 3 min jobs. This stuff is by no way meant to sit in your engine for long periods of time, let alone drive for 250 miles.

If some arse hole said this was good, he needs to read labels or take a tech course of some sort. :eek:

https://www.amazon.in/STP-62450EN-Engine-Flush-450/dp/B0095KKXB2
 

big al

Hero Member
Joined
Aug 27, 2007
Messages
277
Likes
2
Points
18
#9
After digging into the motor more and getting it apart to do intake gaskets it was actually pretty decent inside. I found most of the sludge in the oil fill cap and PCV area. Drained all contents from pan while doing job and inspected oil after, all looked ok, think i may have caught this one in time. Found oil called Prime for cheap and did a top end rinse with it then drained and refilled. I still wanna see this car in 250 miles for another oil change.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
8,565
Likes
137
Points
63
Location
St-Hyacinthe, Quebec, Canada
#10
After digging into the motor more and getting it apart to do intake gaskets it was actually pretty decent inside. I found most of the sludge in the oil fill cap and PCV area. Drained all contents from pan while doing job and inspected oil after, all looked ok, think i may have caught this one in time. Found oil called Prime for cheap and did a top end rinse with it then drained and refilled. I still wanna see this car in 250 miles for another oil change.

This is more of a sensible reply. . Yep, exactly what needs to be done.
 
Joined
Aug 28, 2007
Messages
4,698
Likes
18
Points
38
#11
Last time this happened to me was in my 37 Olds flat head six with a leaking head gasket, pistons were seized, but easy to take apart and hand clean, even found a buck to buy a new head gasket. They have cleaner now? Still pour in one ounce per quart of oil Seafoam a couple hundred miles before changing the oil to keep the engine clean.

When I saw GM and others were using a plastic intake manifold in a V-6 or 8, not only walked away, but ran, its thermo expansion is way different than cast iron or aluminum. Guess if everybody did this, would have stuck with metal. Not bad on a four, fits flat on the head and no coolant in there. But good to check the bolts occasionally.