Jump to content

weird sound from engine bay


Pbpredator
 Share

Recommended Posts

My 1995 Nissan pathfinder is making a funny sound (going to try to post video tonight) but for now ill try to describe it. Its a fluttering whistle ticking that gets louder/worse with increase on rpm also gets worse if im going down a decline in gear without giving gas(under load?) Also this sound goes away over long trips or when warmed up? Started very slightly at first Some say its a lifter? But dohc doesn't have lifters right? Others say exhaust leak? Not sure... but I think I have read a lot of people saying an exhaust manifold gasket leak? So... a friend has said to do an oil change use thinner oil and use Lucas he said it will quiet right up. But if its the gasket... I was wondering if some one would give me a complete list of items needed for this gasket replacement? Would help a ton!

Link to comment
Share on other sites

Kinda sounds like an exhaust manifold leak, yeah. Unless you put a funky engine, you don't have DOHC, and you do have hydraulic valve lifters though :)

 

You might be able to just tighten the exhaust manifolds, they can loosen. Even if this doesn't solve your problem, it might change the noise slightly, which would at least tell you if you found the problem. To actually replace them you need to replace the gaskets... and possibly the manifold to downpipe gaskets too.

 

Lots of people have broken exhaust studs though... which means you might need some more of those, and potentially have a huge pain removing the old ones...

Link to comment
Share on other sites

If its an exhaust leak, no oil change in the world is going to help. Also, your Pathy isnt DOHC. Its a SOHC engine. As for the exhaust gasket, there a good chance the studs have broken, its a common problem among our Pathfinders. There are multiple threads on the studs around here, just use the search function

Link to comment
Share on other sites

My 1995 Nissan pathfinder is making a funny sound (going to try to post video tonight) but for now ill try to describe it. Its a fluttering whistle ticking that gets louder/worse with increase on rpm also gets worse if im going down a decline in gear without giving gas(under load?) Also this sound goes away over long trips or when warmed up? Started very slightly at first Some say its a lifter? But dohc doesn't have lifters right? Others say exhaust leak? Not sure... but I think I have read a lot of people saying an exhaust manifold gasket leak? So... a friend has said to do an oil change use thinner oil and use Lucas he said it will quiet right up. But if its the gasket... I was wondering if some one would give me a complete list of items needed for this gasket replacement? Would help a ton!

 

That's an exhaust manifold leak. Also, this engine is a SOHC not a DOHC.

 

jheadsassembled.jpg

 

Source: http://redz31.net/pages/headwork.html

Edited by Tungsten
Link to comment
Share on other sites

If its an exhaust leak, no oil change in the world is going to help. Also, your Pathy isnt DOHC. Its a SOHC engine. As for the exhaust gasket, there a good chance the studs have broken, its a common problem among our Pathfinders. There are multiple threads on the studs around here, just use the search function

 

 

I meant he said it would get rid of the sound if its a lifter... (because most likely it wasn't getting oil upon start up) In any case im going to do an oil change tonight and use gunk engine flush then use 5w-30 2.8 quarts and 1 quart of Lucas oil stabilizer see what that does... then I will replace all the exhaust gaskets and tomorrow maybe the exhaust manifold gasket...

 

 

Also no to the check engine light last time I checked.

Edited by Pbpredator
Link to comment
Share on other sites

I've read that with the design of our engines, the Lucas stuff causes little bubbles in the oil and chews things up. It's not something I'd put in mine without doing some research.

 

Better to figure out what the actual problem is, before it gets worse!

Edited by Slartibartfast
Link to comment
Share on other sites

I hear two things. The ticking when you rev it, and the "choking" when you let off the throttle. The ticking sounds consistent with exhaust to me, but hard to tell for sure. The choking is likely different than mine since you don't have a stock intake, but I wonder if it's the EGR as suggest by silverton. Perhaps try pinching off the hose to the EGR valve (I used vice grips) to prevent it from operating temporarily, then rev the engine as before and see if it sounds different.

Link to comment
Share on other sites

Be very careful as to not confuse exhaust ticking with spark knock. Those two sound very similar but are completely different problems. An exhaust tick will be more consistent while a spark knock only occurs under certain rpms and certain load.

Link to comment
Share on other sites

100% exhaust leak check it at the egr but like mentioned before it is probably an exhaust stud loosened or broken, now is a good time to think about headers and do some research on here to fix it yourself which can take most in experienced wrench turners days a shop will charge u anywhere from $300-$600 just to fix the one side, i did headers and fixed all my bad studs (used the 350z turbo studs) my self with the engine out on a stand and i still had 8 hours of time

Link to comment
Share on other sites

100% exhaust leak check it at the egr but like mentioned before it is probably an exhaust stud loosened or broken, now is a good time to think about headers and do some research on here to fix it yourself which can take most in experienced wrench turners days a shop will charge u anywhere from $300-$600 just to fix the one side, i did headers and fixed all my bad studs (used the 350z turbo studs) my self with the engine out on a stand and i still had 8 hours of time

 

 

yeah was kind of afraid of that. I have no choice but to do it myself though... I have like no money but like i said i can get parts really cheap and I have a work shop to myself to use to do everything... Im just very inexperienced and kind of afraid of going out and taking the engine out... :/ can i replace the headers without taking the engine out? i have the exhaust manifold gaskets on the way... and i have all of these gaskets already 12960.gif so I'm gonna try to replace those sunday.

Link to comment
Share on other sites

I agree with staying away for the Lucas Oil Stabilizer! I used the stuff on my last motor at the suggestion of a 'mechanic' and I threw a rod right out of the oil pan 200 miles later. No advances warning, No knocking...just a quick vibration through the steering wheel and A LOT of oil on the ground ! Spun all of the rod bearing's too. What was left in the pan, coated the sides like thick honey or STP oil treatment ! lol.

 

I also later discovered that there are 2 types of the stuff. 1 for petroleum based oils, and one for synthetic, which is what I added to my Mobil 1 full synthetic. Either way, it was an exspensive lesson.

Link to comment
Share on other sites

100% exhaust leak check it at the egr but like mentioned before it is probably an exhaust stud loosened or broken, now is a good time to think about headers and do some research on here to fix it yourself which can take most in experienced wrench turners days a shop will charge u anywhere from $300-$600 just to fix the one side, i did headers and fixed all my bad studs (used the 350z turbo studs) my self with the engine out on a stand and i still had 8 hours of time

Forget the 350 studs go get a set for a vg33 they're 10mm instead of 8. drill and tap each hole put the 10mm in bore out the bolt holes on the headers (they are really really tight if you don't) and install.

Link to comment
Share on other sites

The hissing is from that cone filter you got there. What happened to the stock air box?

 

In the other video where you rev the engine it sounds like a misfire. Check for a dead cylinder and if it's not dead then it's the exhaust studs.

Edited by Tungsten
Link to comment
Share on other sites

i had to drill some out to the larger vg33 style studs aswell probably almost half but the 350z ones are a better grade material for the extra turbo weight and heat so theres a mix and they have held my pacesetter headers on for almost 3 years also i used new gaskets and the high heat copper silicone that stuff alone can almost keep a header on

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...