Cadillac Catera and Cimarron Forum Discussion, Rocker Arm Noises in Past Cadillac Vehicle Discussion; 1999 Cat with 93,543 miles. Going across KY into WVa when I got a lot of "rapping" under the valve ...
1999 Cat with 93,543 miles. Going across KY into WVa when I got a lot of "rapping" under the valve covers. I am in dier need of advice before I proceed. I have at least 500 miles more to go before I get home. Oil pressure is good, not over heating, plenty of power. No lights, bells, or SES lights. No apparent leaks or anything. Actually oil pressure is a tad bit hgher than normal. What options do I have to get the car home? What can I expect to have to pay to get this fixed?? I need to get my wife's car home . . . . .
This car would not have rocker arms since it is an overhead cam design. If you are not getting any check engine lights or other warnings and the engine is otherwise running well, re-check the source of the sound. Maybe slack in the serpentine belt, the alternator, water pump, etc. If you can, hook up a scanner to the OBDC port.
Is it possible that something has gone out of sync? My brother had a mechanic listen to it and he said it sounds like there is no oil getting to the top half of the engine. He can't seem to figure out why it would do it on both sides of the engine. It almost sounds like something may have gotten blocked and has interupted the oil flow. I originally thought it might be the oil pump but I have great oil pressure. As I said earlier the oil pressure actually went up after the "incident" happened. That is why I was thinking of a blockage. What am I missing?? I am completely blaffled . . . . .
I just got my 00 Cat, and it has the same issue. But I feel it is a blockage to the upper end of the engine, slowing oil flow down to the lifters / tappets.
Is it quiet when you first start it, then gets loud after about a minute or two?
I was just talking to my Dad, who is a former Pro racer for Chevrolet. He feels the same thing, that oil pressure is lost at the top end, most likely from old oil getting too hot, and blocking some of the oil galleries, passages. He recommends switching to a full synthetic oil, as it will have high temp tollerences, and detergents to help free up the blockage.
I plan on changing the oil again, even though I only have 100 miles on it. Catching the old oil in a clean pan. Filtering it with coffee filters, and re-installing it. I got a case of oil filters for the car, so I'll change it a few times.
But, most likely, it will need new lifters / tappets. If you're going to do that, do the timing belt as well.
It is not that loud when you first start it, but once it is running and you give some gas it gets substantially worse. It sounds like a 6-cylinder trying imitate a diesel (and currrently it is doing a real good job)!
Update: ok after discussing it with my brother we decided that we would do the oil change and run the new synthetic through the system. Now the problem is this. While this was going on he said they heard a "snap" or "crack" and then it rough idled and basically sounded a whole lot worse.
Question: timing chain break? tooth? teeth?? I am not sure I want to know how much this is going to cost. I am looking for some help and/or advice from you fine folks. Please help me figure this out. It doesn't help that there is 430 miles between me and the car and I don't have time (started new job) to take a week to go down there and figure this out.
Hmmm, could have skipped a tooth on the belt. I wouldn't drive it.
What I would do, is first turn the engine over by hand (ratchet) and see if you have any "hard" spots, to see if any valves bent. I would also do a compression test, or leak down test. All of that is easy to do, if you can get to all the plugs. (haven't pulled mine out, so I'm not sure how hard it is to access all 6)
A snap sound, or crack sound, and rough idle doesn't sound good though.
A leak down test is best, but if you never did one, I would just do a compression test instead. Each cylinder should be above say 100 psi, and all be within +or- 10 psi. at very least. I like to see above 110.
I'm also not sure if our cars have an inspection cover for the timing belt or not, but I would look to see what condition that belt is in.
With that many miles most likely the idler pulley on the timing belt gave, and that bearing in there can make some nasty noises. Also the car does have close to 100k so its due for timing service... and that can be a 400-500$ job. Good thing you sold it, the next fella will have his plate full with it...
I would have tried some MMO in the system that can always clean up some of the passages blocked by dirt and allow proper oil to flow to all of the lifters on your car.
Just an update. My brother got a call back from the guy we sold it to. Was asking about the local junk yards looking for an engine. Said the problem with the engine was it was basically "fried". I am so glad we sold it now. She had her surgery and my truck is paid off next month. I will be looking for a convertible for her next. . . .