Rodeo 3.2L SOHC valve train noise


mahounsel
06-01-2005, 05:53 PM
Have a 1995 Rodeo 3.2L SOHC with 170,000. Engine runs fine but has developed a load valve train noise (ticking) up to 2100 rpm and then it abruptly goes away. Have been running 5W30 Mobil 1 plus Tufoil additive since purchased at 110,000. Engine should be staying clean. Tried 15W50 Valvoline for high milage engines, no change. If it was a sticking hydraulic lash adjuster, why would it stop making noise at 2100 rpm. Oil pressure is normal and it doesn't use much oil. Any ideas?

Canucklehead
06-01-2005, 07:19 PM
Have a 1995 Rodeo 3.2L SOHC with 170,000. Engine runs fine but has developed a load valve train noise (ticking) up to 2100 rpm and then it abruptly goes away. Have been running 5W30 Mobil 1 plus Tufoil additive since purchased at 110,000. Engine should be staying clean. Tried 15W50 Valvoline for high milage engines, no change. If it was a sticking hydraulic lash adjuster, why would it stop making noise at 2100 rpm. Oil pressure is normal and it doesn't use much oil. Any ideas?

Bad tiiming belt tensioner.

mahounsel
06-01-2005, 08:01 PM
Bad tiiming belt tensioner.

Thanks. I've read your threads before where you've observed that tapping noises that go away as RPMs increase may be a sign that the tensioner is failing. We replaced the timing belt last year but I don't think we replaced the tensioner.

Trying to understand the symtoms, does the hydraulic pressure in a worn tensioner build up at higher rpms and the tensioner functions properly. Then at lower rpms it does not maiuntain proper tension on the belt.

I hope you are right because the tensioner is easier to replace than tearing into the valve train. How can I be sure the tenosioner is the problem. Can it be tested after removal or is the wear visual?

anthonyn
06-01-2005, 09:42 PM
Thanks. I've read your threads before where you've observed that tapping noises that go away as RPMs increase may be a sign that the tensioner is failing. We replaced the timing belt last year but I don't think we replaced the tensioner.

Trying to understand the symtoms, does the hydraulic pressure in a worn tensioner build up at higher rpms and the tensioner functions properly. Then at lower rpms it does not maiuntain proper tension on the belt.

I hope you are right because the tensioner is easier to replace than tearing into the valve train. How can I be sure the tenosioner is the problem. Can it be tested after removal or is the wear visual?


A mechanic's stethoscope or the 'broomstick to the ear' approach can help to isolate the noise. Why go thru the trouble of replacing the timing belt without replacing the tensioner? Tensioner goes out more frequently then the timing belt....from what I've seen.

mahounsel
06-02-2005, 10:31 AM
A mechanic's stethoscope or the 'broomstick to the ear' approach can help to isolate the noise. Why go thru the trouble of replacing the timing belt without replacing the tensioner? Tensioner goes out more frequently then the timing belt....from what I've seen.

I wish I had a better answer for your question....we just did not know better. If we can be certain that is the problem, I will actually be relieved, and we can change it out this weekend. The noise is not a ticking but a rather load tapping that sounds like it is inside the passenger side valve cover.

If the tensioner has failed, is that obvious by hands on inspection?

Canucklehead
06-02-2005, 11:32 AM
If the tensioner has failed, is that obvious by hands on inspection?

I'm not sure whether or not removing the timing cover and checking the slack in the belt will tell you if the tensioner has gone bad or not.

mahounsel
06-02-2005, 12:24 PM
I'm not sure whether or not removing the timing cover and checking the slack in the belt will tell you if the tensioner has gone bad or not.
Steve,
Based on the described symptoms and the age and mileage on the original tensioner, if it were your vehicle would you try replacing it before focusing on the valve train? The loud tapping developed suddenly while driving not like you would expect a lash adjuster to fail.

Canucklehead
06-02-2005, 01:21 PM
Steve,
Based on the described symptoms and the age and mileage on the original tensioner, if it were your vehicle would you try replacing it before focusing on the valve train? The loud tapping developed suddenly while driving not like you would expect a lash adjuster to fail.

Considering that you have 170K miles on the original tensioner and given your symptoms, I would definitely replace the tensioner (and water pump if that is also the original) before I started thinking about it being valve train noise. When I had the timing belt and tensioner replaced (@ ~120K miles) it was because I started to hear the belt slapping on the cover, much like you are describing.

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