engine noise

[j30tman]

Hey guys, I have found this website to be very helpfull and have fixed most of my cars issues(front bushings, radio, dash lights and headlights) with the help of this forum.

Car: 1993 J30t 119k

Problem: The engine makes a rattling noise from the top of the engine. It almost sounds like two gears with a bad mesh. The noise is most noticable right off of idle and then kinda goes away as the RPMs go up. The engine runs great at all tempuratures and never overheats. I think the noise is comming from the drivers side intake valve cover. It might be coming from the timming belt area too. I have reciepts for the timing belt replacement at 80k. I have only had this car for about two months and need some answers. I would like to save the cost of taking it to the dealer.

Thanks for the help,
Jason

[Underground_Killah]

you may want to check your air intake sensor, if it's gasket is off by anything it'll cause crazy shit to happen with crazy horrible sounds.

[Nahkapohjola]

Originally Posted by j30tman

....a rattling noise from the top of the engine. ....

Take a screwdriver. Place it on various parts on running engine, ear on handle: u can listen and pinpoint the source. Next find from manual whats in tHere....

Go to stealership and ask for quotation. Then go somewhere else to get it repaired for 1/3 price. Ask ppl for a reference for a good shop...

- If the problem is valve lifters, buy original Nissan oil filter, replace with oilchange. Before that, DIY Clean engine oil channels with seafoam.

- If the noise has been since belt change, might be that round teeth belt has been used on square cam sprockets: stealer$hip had done this to my max, no other problem but noise.

[j30tman]

I bought a stethascope today and listened to the motor. The noise is most noticable from the front of the drivers side valve cover and the front center of the engine. I'm still not sure exactly what it is. I've heard that there are springs in the cam sprokets? What sounds do they make when they go bad? I plan on changing the oil this weekend and flushing the engine. what should I flush it with?

[Nahkapohjola]

Originally Posted by j30tman

I bought a stethascope today and listened to the motor. The noise is most noticable from the front of the drivers side valve cover and the front center of the engine. I'm still not sure exactly what it is. I've heard that there are springs in the cam sprokets? What sounds do they make when they go bad? I plan on changing the oil this weekend and flushing the engine. what should I flush it with?

I think its very cheap to have nissan engine specialist to listen and give an idea if its the valve lifters, R&R price. In right place the cost is 0$, takes 1minute. Ask their opinion which cleaner is best; seafoam is one known trademark (carefully follow written instructions). Afterwards change to original Nissan oil filter.

You may download any nissan manual [havin V6] and seek pics for hydraulic valve lifters, theyre about the same in all. (See Links also on my web page.) Small 'cylinders with imbedded pistons, spring' that are filled with oil: system automatically adjusts for valve gap - temp compensation.

119k is NOT a typical time for lifters to go. However, if oil flow becomes restricted, they may go bad during 1k...

(Dunno if your engine has Variable Timing Cams VTC's. Theyre known to go bad: system may be disabled via grounding. Loose 9hp over 5000rpm....)

[j30tman]

Well, I do know that my car has the VTC. Will my engine make noise if it doesn't work? I think that it does work though. I can feel the power increase in high rpm. I am lost as to where the noise is coming from. I am going to call around the dealers to see what it will cost for them to tell me whats wrong with it. I have done a couple of engine rebuilds in the past. These are mainly basic(old) domestic engines though. Need to get it fixed... it worries me.

[sparkeykev]

I had a noise like that in my Maxima j30 3 litre v6 was hydrolic lifters ran an engine oil flush and replaced oil I used Penzoil 10w30 did it again at 1000 km (600miles) has been great since the v6 needs regular oil changes and use good quality hi spec oil

[j30tman]

Thanks for the replies guys.

Well I have not done the engine flush yet, but I am going to try to get it done sometime next week. I am taking my '66 mustang to the dyno this weekend. It has been taking most of my time. I'll post up the results of the flush when I get to it.

[Demoman442]

J30tman....Did you ever find out what the noise was cause mine is doing the exact same thing??? Thanks in advance.

[Demoman442]

I talked with a well known Infinity tech that works at the dealership, Before I could finish my sentence he says the noise is the timing belt tentioner bottoming out because the belt is about to go. I just got the car it has 137k and I don't know the history so it's t.b time!

[swimshark]

unless it is really loud. it is most likely just a lifter tick. i have heard it on mine and my 2 friends 300zx TT. not a big deal to me.