3.5 swap: what the he!l is this noise???
09-22-2006, 04:26 PM
#1
3.5 swap: what the he!l is this noise???
I've put around 1,500 trouble-free babied miles on my '97 after the 3.5 swap. Roughly 1.5weeks ago, I began to hear a very faint "whining" noise which would increase as the revs increased. In the past 3 days, the whining has increased to the point where the car almost sounds supercharged. It's clearly NOT electrical in nature but, rather, mechanical. I've removed both drive belts to see if the noise vanished when the crank pulley rotated on its own...it remained the same. The car runs beautifully, idles perfectly, doesn't use oil and the oil light ALWAYS goes off almost immediately after startup.
I drove the car to my local mechanic for a 2nd opinion...he put a scope on it and said that it sounds as if it's coming from the front bank timing area (louder at the inner case than the outer). I'm using the 3.0 gear with StephenMax's spacers and a new Nissan water pump, chain tensioner and main guide...the chain, sprockets and other guides were all in essentially new condition with no noticeable wear. Everything was torqued (and retorqued) to Nissan FSM specs. He suggested that I stop driving the car immediately, which I have done. I would compare the noise to a squealing sound produced by a dying bearing of some kind...it's as if part of the motor is oil-starved. I'm running 5W-30 Royal purple (-1 quart) with 1 qt. of Lucas synthetic oil stabilizer. There has been a very brief amount of "clatter" at cold startup since the swap was completed. It appears that several members experience the same thing and that it is nothing to worry about.
The only other thing I should possibly mention is that I've had a multiple cylinder misfire code since the beginning, however, the car has always run flawlessly and the motor had only 600 miles on it at the time of installation. When I check the oil (daily) after the engine's been running (or remove the oil filler cap and look at the cams), it is clear that oil is circulating very well (through the heads and block, anyway). Any ideas/suggestions guys?
I drove the car to my local mechanic for a 2nd opinion...he put a scope on it and said that it sounds as if it's coming from the front bank timing area (louder at the inner case than the outer). I'm using the 3.0 gear with StephenMax's spacers and a new Nissan water pump, chain tensioner and main guide...the chain, sprockets and other guides were all in essentially new condition with no noticeable wear. Everything was torqued (and retorqued) to Nissan FSM specs. He suggested that I stop driving the car immediately, which I have done. I would compare the noise to a squealing sound produced by a dying bearing of some kind...it's as if part of the motor is oil-starved. I'm running 5W-30 Royal purple (-1 quart) with 1 qt. of Lucas synthetic oil stabilizer. There has been a very brief amount of "clatter" at cold startup since the swap was completed. It appears that several members experience the same thing and that it is nothing to worry about.
The only other thing I should possibly mention is that I've had a multiple cylinder misfire code since the beginning, however, the car has always run flawlessly and the motor had only 600 miles on it at the time of installation. When I check the oil (daily) after the engine's been running (or remove the oil filler cap and look at the cams), it is clear that oil is circulating very well (through the heads and block, anyway). Any ideas/suggestions guys?
09-22-2006, 08:19 PM
#3
Like your mechanic says do not drive it what so ever, from what your saying it will only get worse. I mean you have been driving it for 1,500 miles and then all of the sudden. So in that case something has failed or is wearing out.
If it's a noise coming from inside the timing case your just going to have to diagnose it a little harder with a scope and try and pin point the source from which it's coming from as best as you can. I can only predict that your going to sooner or later have to pull the timing cover off.
From my previous experiences with such noise your describing 9 out 10 it's the Cam Sprocket, water Pump Bearing or the most popular problem the mechanic put to much RTV sealant on the inner cover and clogged some of the oil passage ways resulting in oil starvation in the most critical areas where oil needs to flow such as sprockets tensioner etc.
Good Luck.
If it's a noise coming from inside the timing case your just going to have to diagnose it a little harder with a scope and try and pin point the source from which it's coming from as best as you can. I can only predict that your going to sooner or later have to pull the timing cover off.
From my previous experiences with such noise your describing 9 out 10 it's the Cam Sprocket, water Pump Bearing or the most popular problem the mechanic put to much RTV sealant on the inner cover and clogged some of the oil passage ways resulting in oil starvation in the most critical areas where oil needs to flow such as sprockets tensioner etc.
Good Luck.
09-23-2006, 05:30 AM
#5
I was going to try Kevlo911's suggestion first...changing to Castrol 10W-30 (although I honestly doubt it'll make much, if any, difference). I did all the work on this swap myself and I'm VERY **** retentive when it comes to this sort of thing. Regarding the application of RTV, I literally sat in front of my computer and looked at the FSM RTV sealant application instructions as I was doing it. I paid strict attention to the bead thickness, protrusion, etc., so I'm very confused. I even did the inner case over because I thought I could do it better the 2nd time around. This new development with my car has convinced me to stop doing s%it to cars and just leave them well enough alone. My Max ran perfectly b4 the swap, but I just haaaaaad to have more power...what an idiot 
. Thx very much for all the suggestions, guys. Any others?
. Thx very much for all the suggestions, guys. Any others?
09-23-2006, 12:51 PM
#7
Hey...anyone know the phone number for Stabone? He's in town this weekend and called me to stop by and check out my car. His number didn't register on my cell and he didn't leave his cell number. I'd like to take him up on his offer. Thx...Steve.
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