Engine noise

[MAX1MVS]

I've had my 94 Montero for close to a year now and one thing that drives me absolutely bonkers is the fact that the engine sounds like a freakin sewing machine. Any ideas as to what this may be?

 

[zukrider]

well, honestly it could be a lot of things. but, if it is what i think you mean, it is the t-belt tensioner. they are called a grenade for a reason. they are a hydraulic tensioner, that after some time, the internal pressure seal gives up, and the tensioner kind of smacks itself. there is no immediate danger to the belt tossing off, unless the sounds really increases to very loud. the grenade should be replaced everytime the belt is. but they dont always last as long as the belt does. i hear ya on the nuisance factor.

 

[MAX1MVS]

Would this give off a tick tick noise that seems to match the RPM's?

 

[off-roader]

Would this give off a tick tick noise that seems to match the RPM's?

I haven't heard to too many of them having problems. Let me rephrase that... "If the Belt tensioner is replaced when its supposed to (60K timing belt changes) then they don't typically have problems."

Does the sound come from the top of the engine? If so, it can be your valves tapping.

When you rev it after idling for a while, does the tailpipe billow black/grey smoke? How about during a cold start, do you see a puff of black smoke? If so, your valve guide seals are very likely toast. When they wear out, they allow oil into your cylinders which burns off. During normal driving, it's not usually a problem until you stop at a light for 30 seconds or more or when you start if for the first time after the engine has had a chance to cool off.

When the valve guide seals go out, what most don't do is regularly check their engine oil levels and when the level goes low from the valve guide seal oil loss, the cams and other parts on top become starved for oil and start to tap. Also some believe the oil passages to the top on some heads (I don't recall if the later 3.0L and 3.5L are one of them) are designed too small and dont allow oil to pass to the top especially if the oil is allowed to get very dirty (i.e. poor oil change schedule).

 

[MAX1MVS]

My dad took a listen (former mechanic) and said it sounds like the valves. After reading the Chiltons it sounds like the monty has some sort of valve lash tension. I am no mechanic, but I also am not afraid to get into it. right now I am looking for a starting point.

No smoke...yet. Upon replacing the radiator last weekend I noticed a crapload of gunk on the inside of the skid plate making me think there is an oil leak somewhere.