98 V70 exhaust manifold - Whats a good part?

[98v70dad]

My 98 V70 has been making a buzzy droning noise now for about 18 months. I've replace every one of the engine mounts and its still droning away. I'm tending toward thinking that its an exhaust leak at the volutes on the exhaust manifold since that is where the noise seems to be coming from. When I did a seafoam treatment a few months ago white smoke pour out from beneath the heat shield. I've had the exhaust inspected for leaks at Midas and none were noted. It was a free inspection so I wouldn't call it thorough. They put the car up on the rack while it was running and looked down the length of exhaust and declared it great! The guy even let me walk the length of the exhaust pipe with him and I agreed that it looked good. Since that time I've inspected fairly closely for crack by sight and feel and have never found anything. Neither of these inspections looked at the exhaust manifold though.

So tomorrow I'm going to remove the heat shield and take a close look with special attention to the volutes on the expansion portion at the bottom.

If I find that its cracked what is a good aftermarket part if there are any?

A used part in this location makes no sense to me since I don't want to do this job again while I own the car. A good quality aftermarket might make sense because I don't plan to keep the car beyond 5 years. I can get the OE part from the dealership near me for a fair price but I don't need a part that will last 20 years.

[kahl]

I have used a piece of tissue around the manifold to discover leaks. The tissue will flap when encountering a leak. On two cars the exhaust manifold gasket failed between cylinder 2 and 3 on the bottom. Use the tissue from the flex joint going up the the manifold.

[abscate]

Once you have it off, the best solution is just to have it welded up by a good welder - cheaper, and it will last your 5 years easy. Im not sure there are aftermarket manifolds?

[98v70dad]

Once you have it off, the best solution is just to have it welded up by a good welder - cheaper, and it will last your 5 years easy. Im not sure there are aftermarket manifolds?

Thanks, welding may be the cheapest solution but it isn't the best one for me. This is my daily driver and I can't afford to have it out of service while I wait to get the part welded. I work about 40 miles away from where I live and there is nobody at work who could give me a ride.

That's why I asked about recommended replacement parts. I've already decided I don't want to get it welded.

[98v70dad]

I have used a piece of tissue around the manifold to discover leaks. The tissue will flap when encountering a leak. On two cars the exhaust manifold gasket failed between cylinder 2 and 3 on the bottom. Use the tissue from the flex joint going up the the manifold.

Good tip. Thanks. I may just be leaking from a gasket but I doubt it. The inspection with tissue will help me nail it down. A smoldering (smoking) piece of paper works too although it might be a bit tight in the engine compartment for that.

The buzzy vibrating drone probably wouldn't happen then. The problem got much worse after replacing all of the engine mounts. I suspect that lifting the engine probably opened up whatever crack might be there.

[98v70dad]

Anybody? Knowing what not to buy would also be helpful if nobody wants to recommend a good aftermarket part. I've searched the site several times and haven't found anything too useful. Someone endorsed the dealer OE part, but that goes without saying. I'm looking for the best aftermarket or OE (non-dealer) part.

[FLXC90]

How bout a clean JY manifold?

[98v70dad]

How bout a clean JY manifold?

Thanks. I'm not really interested in a junkyard part for the following reason. The expansion part (volutes) of the manifold will eventually fail due to cracking. The cracking is due to cycling from movement and thermal heat up and cool down and in certain cases hydrogen embrittlement of the stainless steel. Steel exposed to heat up and cool down cycles eventually gets brittle if conditions are right.

So buying a clean junk yard part means you're getting a total unknown. It may be good for years or it may fail in a week. It seems like a tough job to get the old one out and a new one in so for me rolling the dice and having to remove two manifold and install one is not worth the risk or effort involved. I buy junk yard stuff when the remove and replace effort is fairly easy.

[cn90]

We discussed this issue about 5 years ago.
See the thread below, you may want to ask the people who use OBX to see what they say in terms of long-term reliability.

viewtopic.php?t=45649

[abscate]

How bout a clean JY manifold?

Thanks. I'm not really interested in a junkyard part for the following reason. The expansion part (volutes) of the manifold will eventually fail due to cracking. The cracking is due to cycling from movement and thermal heat up and cool down and in certain cases hydrogen embrittlement of the stainless steel. Steel exposed to heat up and cool down cycles eventually gets brittle if conditions are right.

So buying a clean junk yard part means you're getting a total unknown. It may be good for years or it may fail in a week. It seems like a tough job to get the old one out and a new one in so for me rolling the dice and having to remove two manifold and install one is not worth the risk or effort involved. I buy junk yard stuff when the remove and replace effort is fairly easy.

You can call Erie VoVo and have them remove and ship. Putting one on is easy with new hardware. It's th removal that's the tough nut. This is a pretty decent stacked odds dice roll, like 99:1 in your favour. The number of cracked manifolds on 200-300-400k mile cars here is tiny