Poor Idle - Exhaust leak the cause?

[pvc4life]

So I got my 86 TD up and running and it was running great. I noticed had a very small exhaust leak from the cylinder head to the exhaust manifold (I can visually see where it is leaking). I decided I could live with a small leak for now and was planning on fixing it this weekend when I re-tighten the head bolts (I rebuilt the head and have about 600 miles on the car since putting the head back on).

However, when driving it yesterday the car started running a little rough at idle and I noticed that the exhaust leak is much worse than it was.

I was just wondering if an exhaust leak could affect the car at idle?  I would have thought an exhaust leak would only affect it at higher RPM because of the turbo. I understand it could be something completely unrelated to the exhaust leak but I haven't had a chance to look at it.

Thanks

[8v-of-fury]

Not usually. I have ran one of these engines with no manifolds at all... Intake or exhaust, and it did not affect idle.

Do you have clear fuel lines going from your filter to the pump? Did it persist or go away? Also, when did it happen? after a good higher RPM run and then when you returned to idle it started?

[pvc4life]

Not usually. I have ran one of these engines with no manifolds at all... Intake or exhaust, and it did not affect idle.

Do you have clear fuel lines going from your filter to the pump? Did it persist or go away? Also, when did it happen? after a good higher RPM run and then when you returned to idle it started?

Thanks for the feedback, I didn't think the exhaust leak would cause the poor idle.

I haven't really gotten a chance to troubleshoot it yet. I was going to crack the fuel lines and see if I could narrow it down to one cylinder.

I noticed it when I came off the freeway and came to a stop at a light. I could tell the idle was off and it caused the car to shake a little, but not bad enough to consider shutting it down. I have seen diesels that run worse...

When I started the car again later that day to drive home the idle was still poor and didn't clean up during my drive home. I have no issues starting the car at all. I will check the fuel filter and fuel lines when I get home. I have only had the car for about 3 months, of which the car has only run for about 3 weeks total so I haven't had a chance to go through everything.

Thanks

[damac]

When I got my first 85 jetta td a few years back it was working very well but not maintained.

All of a sudden one day the turbo stopped boosting the same and the engine was loud in the engine bay and you could smell the diesel which sucked.  It sounded like an old vw bug

It seemed to be zipping around town and commuting for about a week just fine  until I fixed it.  Just seemed to be non turbo mode

For me it ended up being a couple exhaust studs had completely backed out, once was broken flush off in the head.  Luckily I was able to easy out that sucker.