I noticed some noise at the right side of the engine. Here is the noise when the engine is cold. Also, sometimes, when accelerating, I hear some slight ticking noise from the right side. I replaced the donut gasket but the noise is still there. Do you guys think I have a crack in exhaust manifold?
Exhaust leak
- Thread starter santon
- Start date
Sure sounds like it. Remove the heat shield and check it out. Use a mirror or borescope to check on the back side. I think @budwich can confirm that even the 08-09 have just as many, if not more, cracked manifolds. It's pretty much a certainty of it if it's louder when it's cold.
At 3, my ears are getting pretty good (hopefully the 4th will last the life of the 2008)... I would say its cracked especially if it does go a bit more quiet once warmed. That just means the crack is still small and that the heat closes it up a bit. As Mooseman suggested, remove the heat shield and check around the cast where the first 3 cylinders "marry" with the last 3.
An update - the exhaust manifold was cracked. I replaced iw with a new one. Also, the first bolt (closest to the firewall) was broken. I even did not touch it with the tool, it was broken from the beginning. Managed to remove other 10 bolts without breaking. I put a new manifold and new bots. Removing the broken bolt seems to me impossible - I don't have the tools to do that, and the space is very tight there. So, I don't hear the leak now but cannot stop thinking about that broken bolt...
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My first replacement was done by gm under the "10 year warranty" program. They took a few days. The reason they indicated was the 3 bolt were broken / broke. The one at the back was one. Not sure how they removed it but the subsequent replacement bolt barely had any threading to grab.... which I found out when I did the next replacement. This last replacement was done by a "private mechanic". He said that there isn't much holding the bolt and figures the next exhaust man replacement would need a removal of the head. That ain't going to happen. There isn't much room back there so even drilling out is tough. For you, (and me) hopefully the other bolts will be enough to keep things happy.
I hope so. Stil, I would like to fix it properly. Let's say I can buy a right angle drill or the right angle attachment to the regular drill. Then maybe I can try to remove the bolt. But it seems it will be necessary to remove the new manifold now. Drilling and using a bolt extractor through the hole of the manifold is probably impossible...
My collegue's GMT800 Tahoo LM7 has the exhaust bolt heads sheared clean off after so many years of heat cycle. On my Saab I can hear exhaust tick and smell exhaust on passenger side.
I ordered this kit to have a fix for now until I can pull engine out. It will arrive today, and I will report whether it works or not.
I ordered this kit to have a fix for now until I can pull engine out. It will arrive today, and I will report whether it works or not.
He has the I6 4.2 so these wouldn't work.
What most people do to remove broken exhaust bolts is weld a nut to the stub.
What most people do to remove broken exhaust bolts is weld a nut to the stub.
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I broke the front one on mine when I did my third unit. I used a right angle drill and a short drill bit (you can cut the shaft to length). Anyway, it took some time as the bolts are "hardened" (either by heat or by nature). I drilled as much out as possible. Of course, the head is aluminum ( I think) so it is easy to damage the area either from a "slip" of the drill or just having to deal with close quarters. I didn't really worry too much at about that (... ya right...
) as I figure I could move up on bolt size go to SAE (which ever was just a bit bigger). I used a tap to make the happen. I used a dremel carbide grinding bit to help a bit. You can't go too much bigger in bolt size as then you will have issue with the manifold hole. Ulimately, if things fail, I guess the next thing would be utilizing a helicoil insert.In terms of the manifold removal, it might be possible to drill out the bolt by using the manifold hole as a drill guide although I am not sure how much room there is back there with it in place. I know even trying to get at the bolt itself with a wrench was tough.
As mentioned, the "usual" method is to weld on a nut and then use a socket to remove the whole affair. Again, that might be pretty tough given the space and the skill involved. As I mentioned, the GM dealership took about 2 days to get mine done and I am sure they know all the "tricks".
Not working, because it's my passenger side, and the AC lines leave no space for the kit. I gave up at 1am. Yawn.
Well, I decided to remove that bolt. Started to drill it out, used different drill bits (3, 4, 5, 6 mm). Tried to use spiral bolt extracftors, without success. Finally drilled to 7 mm, then 7.5 mm and managed to tap with M8 x 1.25. Surprisingly, the threads are OK. However, I created another, more serious problem - I drilled too deep, and get to the coolant passage - the coolant is dripping now from the hole. Do you guys think that black RTV on a bolt could fix this problem?
Not the first time we've seen this, eh @mrrsm ?
There are other engines that have bolts with threads that go into the water jacket. I think the old SBC water pump bolts are like that. I would normally use a thread sealer for that. However, my worry would be heat from the exhaust that would cook it and break the seal. I would try the highest temperature RTV available instead, which I believe is the Permatex Ultra Copper. I would also make sure to use the longest possible bolt without bottoming out so there would be the most possible sealing surface and put some RTV at the end of the bolt so it can plug the hole at the bottom. You would need to lower the coolant level below the head and let the RTV cure before refilling.
There are other engines that have bolts with threads that go into the water jacket. I think the old SBC water pump bolts are like that. I would normally use a thread sealer for that. However, my worry would be heat from the exhaust that would cook it and break the seal. I would try the highest temperature RTV available instead, which I believe is the Permatex Ultra Copper. I would also make sure to use the longest possible bolt without bottoming out so there would be the most possible sealing surface and put some RTV at the end of the bolt so it can plug the hole at the bottom. You would need to lower the coolant level below the head and let the RTV cure before refilling.
It's an idea but would reduce the number of threads available for the manifold bolt. And you could use JB Weld instead if you leave it in there permanently but will be impossible to remove if it leaks again. They do have an extreme heat version which would work well.
www.jbweld.com
ExtremeHeat
J-B Weld™ ExtremeHeat™ is formulated to allow for repairs to iron, steel and metal in high temperature environments (2400°F / 1300°C).
www.jbweld.com
That might work. It could be left there permanently and might be removable if you really heat it a lot if ever you need to remove it again. Check to see if you would have enough clearance to be able to put the manifold on with a stud protruding (or take it off if you're not removing it prior to this repair).
@mrrsm has that info since he did the same thing. He has been MIA for almost a month so I did find this post of his that I believe has the info you're looking for:
And the post following that one he uses a stud and the ones after that he shows some longer bolts and how much they sit above the head surface. And even further he talks about using the Extreme Heat JB Weld for this same repair. It's all a lot of reading though.
And the post following that one he uses a stud and the ones after that he shows some longer bolts and how much they sit above the head surface. And even further he talks about using the Extreme Heat JB Weld for this same repair. It's all a lot of reading though.
That' interesting, I will read!
I went to the local garage and the mechanic, a friend of mine, gave me the stud - please see attached. I think it worked perfect for this situation. Following the recommendations of Mr. Mooseman (@Mooseman, thank you very much!), I covered the stud with Permatex Ultra Copper RTV. Assembled everything, and let the RTV to cure overnight. Tomorrow morning I will fill up the cooling system with a fresh Dexcool. I hope there will be no leak.
I hate such situations. I created the problem for myself. Actually, the exhasut manifold was secured just fine by 10 bolts out of 11, but my perfectionism pushed me to "fix it properly". Now I have a hole in the waterjacket... I learned that indeed, many Chevy, Mopar, Ford and other engines have the ends of the head bolts in the waterjacket,. I've also read that that some modern European (Renault) engines also have the exhaust manifold bolts passing through the waterjackets. So, the thread sealer is applied to these bolts on the factory. Stupid design, I think, but it seems that it works.
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Yes, it seems OK. Of course, I put the heat shield on and cannot see the stud itself, but I don't see any coolant dripping from there or steam.
I think it could be better to put the stud instead of the most front bolt too. Having studs at both ends will simplify the alignment of the gasket and the manifold during assembly in the future. There is enough space for the studs.