Weird engine rattle

[ca18donny]

Hello all,I have just recently had a strange rattle coming from my engine.When I first start it up it dose not rattle at all,but when it gets up to operating temp it has a rattle between 1800-3000 RPM and if it revs any higher than 3000 rpm it gose away.It also dose not rattle at idle.I am at a loss as to what could be making the noise.If it was a rod or main bearing rattle wouldn't it get worse with more RPM?Any help with this would be greatly appreciated.

[Myetball]

Could be any number of things. Impossible to diagnose over the internet. You'll probably get a bunch of guesses and as you run them down one by one you may get lucky and find the problem.

Best be is to take it to someone you trust that knows alot about engines.

A while back I bought a mechanics stethoscope at harbor freight. Worth it's weight in gold in tracking down strange noises. I think it was only a few dollars.

You can also use a piece of hose (around 3/8 to 1/2). Put one end in your ear and the other on areas you suspect the noise. Works better for vacuum leaks though.

[zeeth2800]

hey man i have the same thing happening.i thought it was a bad alternator but that wasn't where the noise was coming from.

please PM me when you figure it out.thanks

[ca18donny]

I just had a mechanic friend of mine take alook and listen to it.He said to him it sounds like the timing belt tensioner or idler pully to him.Has anyone else had something similar to this that can confirm this?

[float_6969]

Your description sounds exactly like failed rod bearing.

Need a vid/sound clip to tell for sure.

[rico05]

I agree with Ryan. Having delt with all kinds of fun noises over the years, the fact that it only happens when warm and in that RPM window leads me to beleive that it is in fact a spun rod bearing. If your mechanic thinks it is near the front of the motor, start with #1.

[ca18donny]

Well if it is a spun bearing then i will probibly buy another ca to swap in so i can take my time rebuilding the current one the way that I want it to be.That way I won't have to drive my turbo prelude(man I hate fwd).

[sjbsuperman1425]

Well if it is a spun bearing then i will probibly buy another ca to swap in so i can take my time rebuilding the current one the way that I want it to be.That way I won't have to drive my turbo prelude(man I hate fwd).

why waste another grand or so on another CA18 when you have another car to drive while you build this one? why not use the money you spend on another CA for parts for the current one?

[boost_boy]

+1 for failing rod bearings. +1 for just rebuilding the CA you have instead of waisting money on buying an engine that's possibly a candidate for a rebuild as well. You say hate FWD, that's your preference, but they aren't that bad. I don't know about your turbo prelude, but I got a couple of CA powered sentras that will smoke your prelude and your CA powered 240sx. It's all about preference as I have 2 CA powered 240s as well.

Dee

[ca18donny]

+1 for failing rod bearings. +1 for just rebuilding the CA you have instead of waisting money on buying an engine that's possibly a candidate for a rebuild as well. You say hate FWD, that's your preference, but they aren't that bad. I don't know about your turbo prelude, but I got a couple of CA powered sentras that will smoke your prelude and you CA powered 240sx. It's all about preference as I have 2 CA powered 240s as well.

Dee

I am not going to try to start a pissing match over whos car is better or faster but before you talk down about someone elses car you should probibly know a few things about it.I did state that I dislike driving my turbo lude but there is more to the story about it.Like it needs to have tags and insurance on it.i do thank you and everyone else that has given me their input on the problem that I am having.

[ca18donny]

Ok I just got home from work and checked every thing out again with a listening device and found the noise to be comming from the area of the # 2 rod.A guy at work told me that I could diconnect the coils one at a time while the engine was making the noise and if the rattle stopped while the coil for that cyl. was disconnected then that would be the one with the bad bearing.I did as he stated and when I diconnected #2 the rattle went away then when it was reconnected it came back. So I guess that I will have to make a decision as what to do now. Dose anyone know of any where to buy a rebuild kit from with forged pistons in it?Lastly Iwould like to seriously thank each and every one of you that gave advice to me about this.

[boost_boy]

I am not going to try to start a pissing match over whos car is better or faster but before you talk down about someone elses car you should probibly know a few things about it.I did state that I dislike driving my turbo lude but there is more to the story about it.Like it needs to have tags and insurance on it.i do thank you and everyone else that has given me their input on the problem that I am having.

It's a FWD thing, so don't take it to personal. They are underdogs and someone has to defend them. My FWD cars are faster than my RWD cars, but each brings a different flavor. Back on topic, if you tear down the engine now, you can save it .

Dee

[ca18donny]

I agree that people underestimate the FWD platform and I used to love the hell out of my lude but then I started driving the 240 with the Ca swap and it was just more fun to me.I am starting to price everything to do a rebuild .I am looking at the kit that import performance parts.com has it is kit number 10.It is $974 with JE pistons.I mean if I am going to go into it I might as well make improvements to it's internals.