HELP! Engine noise, what is it?
 

Started my car today and the engine is making a strange noise... As I turned the key, it even sounded louder than normal while it was starting! Then it fires up, and the idle was louder/rougher than usual... It's noticable at idle, and then as the engine speed increases it becomes more noticable, it's like an extra mechanical noise that almost sounds like valves tapping or a knocking sound, but less "ping" and more "pfffff pfffff pfffff" and it speeds up proportionally with RPM. I drove the car up the street, but then decided to come back and park it immediately. (It didn't feel any more sluggish, but then again I was being easy on it, it was still cold and I was also being cautious because of the noise)

I had the interior apart last night to change the rear speakers, at which time I disconnected the two wiring harness plugs behind the speaker shelf temporarily. I thought maybe something got messed up because of that, but then remembered that I went for a 30 minute drive AFTER installing the speakers and putting everything back together - during the drive, it ran normally. Then today, suddenly it's running rough..

I've checked all the external belts and pulleys, and the exhaust, etc, and found nothing unusual. Could this be related to the distributor belt? I'm at a loss, and I don't want to drive the car to the shop in case it's bad for the engine.

Any ideas would be greatly appreciated!!!! :(

your car is a MY95 right? when the wiring harness started acting up on my MY94 993 it would have a hard time starting - after cranking for a while it would eventually start but would idle and run rough; after a few minutes of driving it would clear itself up and run as if normal. when running rough it almost felt like i had bad gas, a bad spark or water in the fuel. once the wiring harness was fixed it ran fine.

and if it is the "wiring harness" ....you can thank only one person....

EJ........he is the person that got the whole recall done!!!!!!!!!!!!!!!!!!!!!

If not wiring harness, maybe a bad lifter..?

Search for that, lot of good explanation what it sounds like etc.

If you suspect that's the case, try starting again and let the engine to warm up a bit etc. it might go away. Don't drive hard!

Bad lifter, that's what I'm afraid of... I took the dual distributor caps off today to check that the belt hadn't skipped a notch or something, but it was fine. I'm having it flat-bedded over to champion tomorrow, I don't know what else to do!

I had my wiring harness replaced at Champion two months ago (recall)...if yours is still the factory original, chances are it's dying...let's hope for the best...Danny Dimitrakis is my service advisor there...nice guy...keep us posted and good luck...if they don't solve the problem, I'd say you should bring your car to Scott Finlay in Miami...

That's not too bad actually but I'd change at least all lower once since they're the easiest to get to.

And yes, tell them to check if wiring harness have been changed. Even if that's not the problem, have it changed (since your car is '95 and almost for sure is in recall).

pff pff pff sounds like an exhaust leak to me, did you do anything with your mufflers lately?

Phil- Are you serious!?!?! I had no idea! I think that's REALLY cool- here's to the power of Rennlist and our active members!!

Thanks guys again for all your input, I just DROVE back from the dealership... :thumbup:

The mechanic at Champion said it's either the alternator bearing going bad, or one of the fan belt pulley bearings that's making the noise. In other words, nothing internal is wrong, which I'm very happy about... he said it would be hard to pinpoint the exact source of the noise, and to bring it in again if it gets worse. He even gave me the green light for Sebring on the 25th!

I've dealt with Danny a couple times and he is a good guy. As far as the wiring harness, it's the one thing I didn't check for in the records but I will look through the receipts to see if it was done, is that a free replacement because of the recall, even though it's so far out of warranty?

That's the first thing I checked, since I fitted RSR mufflers about 5 months ago I thought maybe something came loose... but everything was tight.

thanks for the input, is this place great or what!

How difficult is it to replace the lower lifters, for someone like me who learns as I go? If one of the lifters does fail, what engine damage will occur? Are they expensive to purchase?

Dealer should be able to check if it's been done through their computer records. It's free, but they usually try to get you to do other things along with the harness, "while we're in there". :D

Not too bad at all, take a look at John D's lifter repair 101 .

He dropped the engine but you don't need to do that.

However since your car is at Champion you probably need to do at least one of them and "since they are there" it would be good to change at least all three that bank's lifters.

I'm planning on doing this to my car fairly soon (even though mine ar quiet), at least all the lower ones. Once I'm doing it, you're welcomed to take a look if you're interested.

Great news! :thumbup:

Harness is free, it's a factory recall so even though if your car is out of warranty, doesn't cost a thing. As said earlier, thanks to EJ!