Minor exhaust leak at exhaust manifold weld

JackC

wrench
Joined
Nov 14, 2006
Messages
1,724
Points
48
Location
Nothern California
Make
Buick
Model
Park Ave
Year
1989
Miles
212,200
Engine
3.8
I failed smog on my California 1989 Buick 3.8. They found a tiny manifold exhaust leak. I saw the smoke from the smoke machine coming out at a weld seam. No noise, no smell and no visual signs. Left side (rear) manifolds are not available. And even if they were they would be out of my budget @$400-$500. Even R &R manifold to be welded is about $400. The state will give me $1000 just to get it off the road.

But I love the car and Billr can contest to it in almost in show condition.

I told the smog station I would fix it with JB Weld or Quick Steal. They said they would not except that type repair. What? Can't I repair it what ever way I wish?

Also, Have any of you had success with 2400* JB Weld Extreme or Quick Steal on manifolds? Those are both a different produce than the original JB Weld.

Or is the regular old JB Weld better?
 
Last edited:

paulo57509

Jr. Member
Joined
Apr 9, 2014
Messages
48
Points
8
No experience with epoxy on exhaust header pipe welds. I think I would use the high temp stuff.

I think it's odd that the state of CA would specify how repairs are made. But it IS CA (I live in this h-hole too).

Just curious; did you take the car to a test only station or a place that also does repairs (this might be shed some light on the last paragraph)? Test only places would not take the time to take out the smoke machine and look for a leak. I think they're prohibited by law from doing so. What made them start looking for a leak? Visual inspection or odd test results?

A quick browse thru ebay showed several exhaust manifolds for ~$60.

Unfortunately, being the rear manifold, it's hard to get to with out tilting the engine forward (where they doing that back in '89?). Even then, it might have to drop the engine cradle to get to the fasteners.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,109
Points
63
This is on a cast-iron manifold? I would try some of that "high heat" stuff and coat it with an oily "mud", let the oil cook on to hide the repair. Obviously, coat a wide area on the manifold so it isn't obvious. Go to a different smog shop that doesn't know what it used to look like.

Do I read correctly, you do not want to pull the manifold for welding?
 

Mobile Dan

wrench
Joined
Mar 1, 2002
Messages
3,763
Points
48
Location
Kentucky
I doubt that any kind of epoxy (JB Weld and all varieties similar are plastic based epoxy) will work on an exhaust manifold. Maybe short term if you idle to the inspection station. Depending on location, you might consider drilling a hole and sticking a screw in it.
 

grcauto

Hero Member
Joined
May 29, 2014
Messages
784
Points
28
Have a welding shop fix it. If they can get at it while on the vehicle they will likely be able to fix it. Maybe braze it.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,109
Points
63
The common JB Weld is steel powder with an epoxy binder, not going to take the heat. However, reading the MSDS for that "high temp" stuff indicates it is steel powder with a ceramic binder that probably fuses under heat.
 

JackC

wrench
Joined
Nov 14, 2006
Messages
1,724
Points
48
Location
Nothern California
Wow, thanks for the quick repIy

It is a STAR station and they also do repairs. I doubt the state can require who or where or how you have it fixed. But the shop owner stated he would not certify a JB type fix. Obviously if I had known about it and fixed before he saw it all would be fine, Now I have paid for his $80 test but not the $8.25 certificatiion. If I replace the manifold he will certify it for the $8.25 If I go to another shop after I do the JB weld I would have to pay another $80 (actually $100 or more around here) to have it retested and certified.

The e-bay manifolds are all used. I already have one of those. I do not need another one. Too risky for me.

It is cast Iron.

At 87 I do not want to R&R the maniflod myself (potential broken bolts and studs) and I hate to pay hundreds for something that IMHO does not even need to be done,

Regular JB weld and the JB Extreme and Quick steal all specifically state good for exhaust manifolds.

Y tube videos show great and terrible results with the Extreme Temp stuff. As Billr says, it is a different type of material than the old two part JB Weld epoxy (Which BTW also specifies it can be used on exhaust manifolds).

Probably more info than you need to know.

The original and real question is has anyone used any of these products successfully on cast iron exhaust manifolds?
.
 
Last edited:

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,109
Points
63
What is access like to this crack, how close is it to the cylinder head? Post pictures. If there is access to even JB Weld it, I'm wondering (like grcauto) if it can be welded in place. It would be risky, and not a terribly good job, since the manifold could not be pre-heated, but the crack might be sealed good enough. I'm willing to give it a try, or at least peek at it for a better -informed opinion. I have a friend who was a superb welder, but he is 83 now and can't see well enough to do it. I could get good advice from him about how to go about it, though.

In regard to your specific question: I have only used ceramic-based "muffler fix" goo; and not of the brands you are asking about. It is rather brittle and with little adhesion. If a joint is mechanically sound it can plug a gap (smoke tight???), but and movement at the joint causes it to crumble away. Epoxies have some real adhesion and (limited!) flexibility, but 500-600F is the top of their limit and is a range that an exhaust manifold will often exceed.

Why did they look for the crack, was it because it failed the tail-pipe sniffing?
 

JackC

wrench
Joined
Nov 14, 2006
Messages
1,724
Points
48
Location
Nothern California
Why did they look for the crack, was it because it failed the tail-pipe sniffing?
I do not know.

Hard to tell exactly where the leak is with smoke machine. The smoke moves around too much. I will pressurize the exhaust with air and then water and soap test to show exactly where it is leaking and send a picture in a day or two. I have guests here this weekend.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,109
Points
63
Did they run a tail-pipe test, did it pass that? If this is only failing because of the perceived crack (a "visual inspection" fail), it is starting to sound like a con...
 

JackC

wrench
Joined
Nov 14, 2006
Messages
1,724
Points
48
Location
Nothern California
Did they run a tail-pipe test, did it pass that?
I have no idea about the tail pipe test. But It really does leak. I saw the smoke after they connected the smoke machine to the tail pipe. No con. Maybe slightly aggressive on trying to sell repairs, but legal IMHO.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,109
Points
63
So, they aborted testing before the tail-pipe test; or did it, but did not give you a print-out of results? You have me worried now that the smoke test for any exhaust leaks is mandatory now, just like the "clamping" of evap system lines became a couple of years ago. I think I'll check with my friendly smog guy Monday...
 

JackC

wrench
Joined
Nov 14, 2006
Messages
1,724
Points
48
Location
Nothern California
They did the entire smog test first with a print out that stated it failed and then because I was so skeptical about the leak, they let the car cool for an hour and did the smoke test at no added cost. I saw the smoke coming out of the manifold.

I do not think the smoke test is mandatory.

If you do ask your friendly smog guy, ask if my smog station can force me to replace the manifold ? It would seem to me that I could take it anywhere or even do it myself in any way that stopped the insignificant leak, including a cold weld.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,954
Points
63
Location
St-Hyacinthe, Quebec, Canada
The original and real question is has anyone used any of these products successfully on cast iron exhaust manifolds?
no
dosnt work.

sorry for blunt answer, but I think that is what you were looking for.

But as usual, I will always disclaim, cuz ya never know.

I usually rod weld with a cast iron stick,, V groove the crack, filler up,

Btw way, hi Jack, hope all is well. ;)

In case here is a link to the rods I use. it is a nickel alloy one from boston sold through canada I think. Cheap and good on stick. I could be wrong, but this supplier is solid.


the 55 works real good on honda civics that crack, they crack so much, you did 1 or 2 a week back in the day.

Anyway, take care, and plz keep us apprised if that JB weld stuff holds up, my lame opinion, it wont,
 
Top