I have a bad feeling about my motor and fear the worse. I have been having a problem around 2000-2500 RPMs with what sounded like an exhaust leak but today I took a good hard look. The first thing I found was the #4 ehaust valve was making a knocking sound so I first atepted to adjust the rocker W/no luck then swaped the rocker with another also with no change then on a sugestion from my friend I installed a stock 1.5 and the noise went away (WTF). so I took the car for a spin and it still made the same damn clacking sound :mad . the #4 rocker is still quiet so now I am rely confused. I just cant seem to get it to make the same noise at idle as i here on the road. To top it all off I do here some kind of low knocking sound at idel but can't locate that either. I have been under the car and every where on the motor I could stick my 3 Ft 1/2'' extention (used it to listen seemed to work better then the cheap stethascope I bought). I have a bad feeling about this whole situation and fear it is either the heads (Valve seats) or worse mabey a rod. Any one have an idea or two? I have great oil preasure and you cant here the sound over 3000 RPMs but I do get random knock counts on the scan master. I don't think it is a rod because I think it would make noise under load at WOT and If I get on it I only here the noise between 2000-2500 RPMs.

 

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The rocker noise may be a bad lifter, and the lower noise could be a spun rod bearing. It is really hard to diagnose over the internet, would be a bit easier if we could hear it run.


Good Luck, hope it isn't anything serious.
MP

 

When I spun my rod bearing, it was making a knocking noise from 2000-3000 rpm. If it was the rockers, wouldn't the noise be there all the time albeit at different frequency?

 

I agree with you on the rocker's but I had some problems with the shop that did the heads. They stuck 2.02 valves in the thing instead of the 2.00's I asked for and from what I understand the valve seats can not be properly cut for the 2.02 valves. I pulled the left head after I read the build sheet and brought it to another shop to take a look and he showed me that the seat was close but said it should be fine. Can you tell me some more about the sound you had when you had te bad rod bearing? The sound I have sounds a lot like an exhaust leak most of the time but when the car gets hot (215 Oil temp) it reminds me of a broke flex plate (I have a 6 speed so this is not the problem).

Thanks for the help