1995 Rodeo sounds like a diesel

[rodeodrive]

1995 Rodeo 3.2L 161k miles. I used to notice a knock at low rpm's and during city driving, if I wound it out above 3500 RPM it would go away for a while. I have switched to a Napa Gold filter and 5w30 oil thanks to you folks.

My knocking has become constant, it really sounds like a diesel engine. Everyone has commented that it sounds like a stuck lifter, but after reading all the posts about timing belt tensioners it makes me wonder if I should start there.

I'm the second owner, and the previous owner said he had the t-belt replaced at 100k, but I do not have any records of that.

I'm going to tear into it this weekend, where should I start? Lifters or T-belt tensioner?

Mike
FL

[Gizmo42]

Valve train would be a tick, tensioner or rod bearings would be a knock.

Does it do it only while moving or at idle as well? Pinging can sound like a knock too but will only happen under load.

Mine was pinging really bad saturday for the first time ever. Was pulling a really heavy trailer. Topped off the tank (was 2/3 full) with 91 octane and it cleared up.

[trooperbc]

Originally Posted by rodeodrive

1995 Rodeo 3.2L 161k miles. I used to notice a knock at low rpm's and during city driving, if I wound it out above 3500 RPM it would go away for a while. I have switched to a Napa Gold filter and 5w30 oil thanks to you folks.

My knocking has become constant, it really sounds like a diesel engine. Everyone has commented that it sounds like a stuck lifter, but after reading all the posts about timing belt tensioners it makes me wonder if I should start there.

I'm the second owner, and the previous owner said he had the t-belt replaced at 100k, but I do not have any records of that.

I'm going to tear into it this weekend, where should I start? Lifters or T-belt tensioner?

Mike
FL

you are asking us to diagnose a sound we are not hearing, so take that in to account.

since, i can't hear it, and since you are unclear about what it might be, although i get the idea that it is similar if not the same noise you have been hearing -- so i'm first going under the assumption it is hydraulic lash adjuster lifter noise. so if you haven't changed your oil in +3000 miles i would start there, change it and see after a bit if it makes a difference again.

if the noise is not the typical lifter noise, and if it is a loud almostlikearodknock, and it goes away after about ~2000 rpm (not always goes away), then it is probably the timing belt tensioner and you need to do the whole timing belt thing -- tb, tensioner, water pump.

you think the tb was done ~60,000 miles ago, so it wouldn't be unheard of to need to do it again, depending on the parts used and whether they did the tb tensioner especially back then.

you can try to pinpoint the noise more using some hose in the ear, long screwdriver, mechanics stethoscope.


tearing into the lifters per se can get expensive real quick. there is a procedure to clean them, but.... also, the other thing to check at that point is the condition of the rocker arms and shafts, where wear maybe has created too much clearance.

the problem with just tearing into this thing from whatever angle, it's expensive and time consuming to do on spec.

maybe give some more description here on the noise under different conditions.

//bc

[rodeodrive]

Thanks for the replies, it does sound like lifter noise to me. Last oil change was about 1800 miles ago, I just added sea foam to the oil on my lunch break. Wow, what a difference, much quiter. I know this thins the oil, but I'll do an oil change early and keep a can of sea foam on hand for the future.

[ibew595]

1994 V6 160k miles with the lifter tick since it went out of warranty. The seafoam helped but not for long. Oil changes would fix it for 1-2k then it would come again. Full synthetic oil would delay the tick out to 5k miles ( I hate to do oil changes). I have moved to using Mobil Delvac 1300 super (diesel oil) which does not lose viscosity and can be used in gasoline engines which delays oil changes even more.
If I could find it, Rotella T synthetic would be my choice. It seems that as soon as the oil loses its viscosity the tick starts up again.