95% sure manifold leak - please confirm

DSrugis · Nov 5th, 2005, 01:13 AM

Since I have replaced the injectors in the Nissan it runs quite well...nice and steady and quiet idle. When I rev the engine up, I hear a ticking noise which I believe, from what I have read on this site, is probably a manifold leak. The truck is a 95 w/ 3.0 and has 130,000 miles. I have no sound at idle but it is there when it revs up? Does this sound like the culprit? Is there any danger besides increased noise if I don't have this fixed?

Dave

johnnyhammers · Nov 5th, 2005, 10:08 AM

Sounds like it, but try the rubber hose trick before pulling the manifold to make sure. The tried and true (relatively at least) method of stuffing a length of rubber tubing in your ear and fishing around the engine bay with the opposite end. this works like a doctors stethoscope, helping you hear an area of about a square inch or so. But do be careful of your hearing, if you find something loud it will transfer that noise directly to your ear, so move slowly and use one hand to put distance between the tube and your ear if necessary.

Good luck
and remember to use a good penetrating oil on your studs before trying to remove them. I recommend a brand called "P.B." "The fabulous parts blaster" it's in a white and yellow spray can with a bunch of writing all over it. Give it a try.

also when you do have it off, inspect the manifold itself VERY closely for cracks as they seem to be rare but they do happen, sometimes in the weirdest places so check every square inch of it. also check the mating surface with a good strait edge to see if it has warped. you can probably get a "new" one at a junk yard for cheap, or have yours machined flat.

johnnyhammers · Nov 5th, 2005, 10:18 AM

also go to the Frontier forum and search for "rubber hose trick". this is a thread that we dealt with a few weeks ago that is just the same question. maybe there is something in there that will help or at least sound familiar.
Good luck.
Johnny

Franko Manini · Nov 28th, 2005, 06:34 PM

Yeah, this sound like the old "busted exhaust manifold stud" deal. You will need to remove the manifold and drill out the old stud (or studs) and then use an extractor to pull them out. It's not as hard as you might think. Jsut make sure you get a nice long drill (they call them aircraft drills).

If you leave it too long, the escaping exaust could mar the surface of your head or the manifold and that would precipitate further leaks in the future. So get in there are take care of it as soon as you can.

Nissan produces studs that are stronger now. I replaced all of mine onmy 88 Patfind when I had the passenger side manifold off. No problems since then.

**88pathoffroad** · Dec 31st, 2005, 07:02 PM

They always did produce stronger studs. They're for the 300ZX turbo V6.