Top End/Valve noise.

[Shane]

Hey guys and gals, I recently bought an 86.5 7MGE and W58 equipped Supra with 196,000mi on it. It recently developed a noise in the top end.
It sounds like valves but I'n not sure. I searched all over google and all over these boards and couldn't find relevant results.

Here's the details:

When the car is cold it starts up fine, runs great and I don't hear the noise.
The closer the engine gets to operating temperature, the louder the noise gets.
I can only seem to hear it between 2,200 RPM and 3,000 RPM loudest being about 2,600-2,800 RPM.
It is louder with more throttle.

I was wondering if maybe the oil was too thin.. I have no idea what kind is in it.
I plan to do an oil change this week and see if that helps. I was going to go with a thicker oil anyway since it is over 150k.

Thanks for any help,

 

[Supraguy7M]

What's the oil pressure when its making the noise the worst? Could b lack of lubrication, Low oil pressure, valve adjustments, old broken down over used oil, any of those can cause some loud "ticking" so to speak in the top end.

 

[Shane]

When its cold its just over the 40 mark. When at operating temperature its under 40, about 1/3 of the way to the mark below. Hopefully there is an improvement when I change the oil.

 

[Supraguy7M]

Hopefully an oil change will help. When the engine warms up the valve clearance gets tighter due to expansion of the metals when up to temp, so unless u have a lubrication issue, you would hear the "ticking" more when its cold. Maybe your oil is breaking down when it reaches operating temp

 

[jake8790]

From your description it sounds like rod knock. Can you post up a vid of the noise?

 

[Shane]

I'm pretty positive it isn't rod knock. I know rod knock lol. I will try to get a vid later today.

 

[Supraguy7M]

From your description it sounds like rod knock. Can you post up a vid of the noise?

if its got a rod knock it should b constant not just when it warms up.

 

[SaltyMKIII]

Its rod knock. Mine did the samething and you didn't hear it all the time and I thought it was just valve tapping so I just drove it that way... little did I know it was number 4 con rod bearing... I found out when I was driving to work and the con rod broke and then I needed a new engine block... just look into it

 

[supraguy@aol]

Not to be negative, but rodnkock does tend to be quieter when the motor's cold, and louder when it warms up.
I was thinking that it could also be a very large valve shim clearance or two, but that would be very very gradual, not something you'd suddenly notice.

 

[emericaskater285]

My money is also on rod knock.

 

[3p141592654]

Pull the spark plugs one by one and see if the knock goes away. If it does, your have found your bad bearing.

 

[hey...it runs]

Pull the spark plugs one by one and see if the knock goes away. If it does, your have found your bad bearing.

I'm with this guy on pulling the plugs. Believe it or not I had a noise develop that almost sounded like an exhaust tick. One day the plug popped out and almost wrecked the threads. I never thought to check their torque. My noise disappeared after tightening all the plugs though

 

[Shane]

I'll give that a try after I do the oil change. Thanks for the input.

You don't suppose it could be injectors? Ive heard of them making noise like that too.

 

[jake8790]

You don't suppose it could be injectors? Ive heard of them making noise like that too.

They make a very light clicking sound, nothing you would be concerned about.

 

[Supraguy7M]

Not to be negative, but rodnkock does tend to be quieter when the motor's cold, and louder when it warms up.
I was thinking that it could also be a very large valve shim clearance or two, but that would be very very gradual, not something you'd suddenly notice.

Well I don't usually end up with a knock, lol, I usually throw a rod if I lose the lower end. I like to rev high lol. But good to know, learning something new everyday

 

[Shane]

Well i did the oil change a couple weeks ago, it's still making the noise, hasn't gotten any worse. Did a drift event for 2 days, raced and beat a mercedes cl230 to 115 mph. Think if it was a rod bearing it would have gone already or gotten worse. I'm really thinking it's valves since it does SMELL like it burns oil even though the oil level doesn't really go anywhere... guess I will be swapping heads at some point in the future.