Clattering noise from front top of engine

[IAS92SHO]

I just purchased a 92 SHO with only 61,000 miles on it. Inside and outside are in mint condition. I just replaced the fuel pump myself, old one was loud, and there was hesitation between 1800 RPMs to 3,000 RPMs. The new pump did not help the rough running in this range however. Upon test driving the SHO a clattering noise appered in the front top portion of the motor. Faint at first but gradually became louder. I was preparing to do the 60K tune up and had all my supplies so i cut the acessory belts a ran the motor and the noise was still present. Can this just be the valves needing adjustment? Should i procede with the 60K service or should i investigate another area of the motor. I had a unmaintained 89 SHO with 90K on it and never heard this noise before. Thank you for any advice.

 

[fredhurderjr]

If by "front top" you mean the head closest to the radiator & the top of the engine (obviously), then plan on the possibility of a cam chain / tensioner being gone.

New chains cost about $50 (list) and tensioners are about $50 (front head) & $110 (rear head) from memory.

If you mean the front of the engine (passenger side), be sure it's not just a fuel injector clack.

Good luck & go ahead with that 60k!

 

[projectSHO89]

Welcome!

Your problem might be the timing belt hitting the cover, bad or missing shim or damaged cam issue, or even the crank/timing belt key issue that has been a very recent topic. There have been several over the last few weeks and reading them will give you much insight into possible concerns.

Pull the upper timing belt cover off and try running the engine. The belt might be stretched and has been slapping the cover (if you're lucky).

Test the crank/timing gear joint by observing the camshaft sprockets (upper timing belt cover removed)as the crank is turned back and forth. There should be no lag in the cam sprocket motion relative to the crank motion. If there is, either the timing belt is stretched or the "crank cancer" has occurred.

If the front end passes its checks, the problem could be a damaged shim or camshaft lobe. An inspection once the valve covers are off should tell.

Good luck.

Steve

 

[BlackOnBlackATX]

i would think its your valves, thats characteristic clacking your hearing. even my chevy does the same thing. you may have taken much better care of your 89 SHO than the previous owner of this 92 did. also id be careful running the car without the belt on since your not getting any water cooling, believe it or not you can f*ck up an engine reeeeeeeeal quick like that. im sure some of the others will be able to offer you some more help but i say its most likely your valves, but still possibly something else. good luck and keep us posted!

 

[IAS92SHO]

I was refering to the front being the end with all the acessories. The fuel filter was in very poor condition and I believe that was why the fuel pump was on its way out. I tried to cycle the pump a number of times but could not hear it run. So i tried starting the motor and it fired up and ran rough for a minute than idled, and then thats when the noise started. What causes fuel injector clack and how do I check for it?

 

[blewbyu]

When you pull the front vavle cover to check the valve lash, be very tideous in checking the front chain tensioner. I had the same problem on my 92. Good luck, Craig

 

[projectSHO89]

The chains and tensioners are on the rear of the engine (driver's side). The noise has been described as coming from the front of the engine.....that's the passenger side.

Steve