# noise - weed eater in there?



## ajriding (May 10, 2010)

I have a high pitched noise. It sounds almost like a faint weed eater engine running, a high pitched rattle.
d-21, 3.0 1986.5
I replaced the water pump, but that was 15 years ago…
Could the water pump be going bad and making a noise?
The noise happens cold or warm, sitting or driving, high or low revs.


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## smj999smj (Jan 1, 2006)

After 15 years, of course the water pump can be making noise (I hope it hasn't been 15 years since you replaced the timing belt)! But, it could be any of a number of things, including an idler pulley bearing, a bearing on an accessory drive, such as the alternator or P/S pump. If you have an auxiliary electric fan, that could also make a similar noise. It's hard to diagnose a noise concern without being able to hear it in person. You could try removing one drive belt at a time and run the engine to see if the noise goes away. IIRC, the alternator and water pump share the same belt. If the noise goes away when you remove the alternator belt, shut off the engine and try turning the water pump pulley and alternator pulley by hand to see if you can feel any play or roughness.


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## jp2code (Jun 2, 2011)

The items SMJ mentioned (water pump, thermostat, timing belt idler pulley, timing belt, and accessory belts) would all be replaced with the timing belt service.

These are interference engines, meaning if the timing belt breaks, the valves will "interfere" with the piston's movement - and you will have engine damage.

The timing belt is supposed to be changed every 60,000 miles per the Service Manual.

If you have not done this service in a while, it would be a good way to take care of that weed wacker in your engine.


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## SPEEDO (Jun 9, 2003)

If you have not done this service in a while, it would be a good way to take care of that weed wacker in your engine.[/QUOTE]

then how is the grass going to get trimmed?


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## ajriding (May 10, 2010)

WATER PUMP!


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## ajriding (May 10, 2010)

WATER PUMP replaced along with other cooling items that needed replacing anyway. I think it must be the valves. Do these need to be adjusted to get rid of the noise or is it just normal?


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## jp2code (Jun 2, 2011)

That sounds like your timing belt. It can stretch over time and the tensioner that keeps it in place inside can wear away.

What sucks is you have to take the water pump off to get at it.


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## smj999smj (Jan 1, 2006)

The hydraulic lifters have been known to make noise in these engines when they start getting high mileage. Assuming oil pressure and circulation is good, the only fix for that is to replace them. Since they are hydraulic, there is no adjustment provision. Broken exhaust studs are common and can make a ticking noise, especially on the right side. It's hard to diagnose on a forum level without being able to hear the noise for oneself.


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## ajriding (May 10, 2010)

I did the timing belt when I did the water pump (had overheating issue so figure can't hurt).
Incidentally, I must have had the belt too tight and the tension adjuster pulley blew apart and made a bad noise as I drove. Replaced that with new one and right tension, but the original sound persist.
This is a 1990 engine in 1987 body. I have never messed with the lifters, but suspect this. Is it bad that there is noise? Do I need to worry about lifters? Mileage is probably 250,000+ (not original engine and I do not know install mileage).
The water pump can stay on for the timing belt change, but timing belt and harmonic damper had to come off for the water pump on these V6s.


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