Gents;
While working on my boy's Aura with the 2.2 engine I noticed the exhaust manifold is cracked.....again. In 2016 I installed a new one I purchased from Amazon. Update to today and that manifold has cracked in the same place. I realize these manifolds are most likely Chinese made and probably inferior to General Motors products but I'm retired and don't have the funds for a GM part. Also, the original GM manifold cracked in the same place so there must be some kind of stress going on in that area. As a side note I notice there are many exhaust manifolds


listed for 4 cylinder GM engines on Amazon. Before I buy another manifold, can anyone give me an idea what might be going on? .....Old Marine?

 

I have no experience with this. I've seen this on YouTube videos, but it seems to be a surprise there too. (I'm afraid to take off the heat shield on mine and see this.) So apparently it's not unusual, and apparently does not significantly affect how the engine runs or engine performance. As for the reason they crack, maybe stress when they get heated and cooled a few thousand cycles. I have noted that the flange at the lower bolts is cut through around the bolt holes, probably to allow for heat stress, but I would think that allows for the 'header' pipes to move independently if there is any slack at all at the lower bolts, contributing to the cracking at the Y.

 

You'll know when there's a problem with the exhaust manifold because it sounds like a mini Ukrainian tank! I noted those splits on the flanges also but only got me to scratch my head Old Marine. As you state many heat cycles combined with the short distance to the flange for the catalytic convertor might b the problem but who knows.....that's for the engineers to figure out. Incidentally, my boy is an engineer but he doesn't know how to work on cars! I guess I will belly up to the bar and buy another Chinese manifold.....at least it should last another 6 years. By then my boy will have to change it himself! Thanks Old Marine

 

You might be able to take it to a welding shop and see if one of the guys there can braze it. I had an uncle with a slant 6 Dodge Dart that the manifold cracked on like that and HE brazed it so it didn't leak. He was an old school, pipefitter and welder. I don't know if shops still do that or not.

 

Rubehyseed; I gave that some thought. I know a great welder who does excellent welds and fast but not cheap!. If I still had the old GM manifold I would give it a try but don't really want to mess with this Chinese manifold.. I go to the junk yards at times.....for therapy....an will keep an eye out for a GM manifold. If I can get it for 25 dollars or so I'll buy it as a back up! BTW you have an interesting posting name. Thanks .

 

After many years of trash talking, I finally met the man last year. I can certify that he is in fact a rube.

Put heat give the last shirt off his back to help you. That's just who he is.

 

Is that manifold actually cast iron, like it looks or is it some kind of composite? If it's a composite, I'd try some good old fashioned JB Weld. I've used it on intake manifolds, drilled it and had no issues. Of course that was on a 70's model Mopar 318 engine.

 

Rubheyseed.; Your are exactly right GB Weld is nothing short of amazing bit I want to be done with the boy's car for awhile. Not entirely sure JB Weld will last that long. Besides, I already purchased another manifold. It's a Dorman product which is still, I'm sure, made in China. However, all that aside. ....while installing the manifold I discovered a broken exhaust stud in the head. I've been able to conquer and fix big problems in the past however, this issue ranks way up there in difficulty. I will try to drill out the stud but have to look at the stud through a mirror and I'll need to have the dexterity of a monkey. At 73 I'm not entirely sure I'll be able to accomplish this without a visit to our local hospital ER! Thanks my friends

'

 

Make sure to cent punch that exhaust stud. There's nothing worse than getting off center on something like that. I have the dexterity of a hippo with thumbs, so I probably wouldn't attempt something like that. I'd probably take the head off and take it to a machine shop if it was me. Good luck with that Dorman manifold. I'm pretty sure that's Chinese junk too.

 

Their little stuff for Saturns are mostly okay. Especially when there are no other options. Their big stuff is usually ****, doesn't quite fit right etc. Although they have seemingly begun to manufacture some Saturn replacement parts that have been unavailable for quite some time. It's not a large market to corner but hey a bucks a buck