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Hi everyone, my 99 Grand Cherokee with a strait 6 has a ticking sound coming from the engine. The ticking is present at all times, cold and normal operating temps. When I accelerate the sound speeds up and starts to sound like a wine. There are no codes, the vacuum test reads steady at 15 lbs. (19lbs. at sea level), and compression test was 120-150-145-120-145-148, no change with the wet test. The best way I can describe the sound is similar to a diesel engine but not as loud. Do you think this is from an exhaust leak, a problem with the valves, timing, lifters, or something else? Thanks.
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Sounds like either exhaust leak or lifter noise from your description. Going by your compression checks, cylinders 1 and 4 are lower than the others and do not improve with the wet check, that sounds like slightly leaking valves, which would not usually cause engine noise.
If you feel you have sticking lifters, you could try an engine flush. However, i am not a fan of ‘mechanic’ in a can but did see one product work on BriansMobile1 channel and here if the link –
http://www.youtube.com/user/briansmobil … RecrxxLT4s
If you can take video please do. I used to work in a record store and got no end of people humming songs to me because they forgot the lyrics. Let me tell you it was an exercise in futility every time. I’m sure mechanics get a similar earful of owners trying to repeat the sounds their car is making. It’s funny at first but gets old real fast. There are different octaves of ticks, clunks, and squeals that even Mariah Carey would be hard pressed to reproduce. If you can take video or audio of an issue it saves everyone a whooole lot of time.
Quoted From twiggy02919:
If my car ever started sounding like Mariah Carey its headed to he junk yard
LOL!!!!!!!!!
Quoted From twiggy02919:
If my car ever started sounding like Mariah Carey its headed to he junk yard
Oh man, I can’t agree more. But to the original poster, those are some semi-odd numbers for compression. Does the vehicle run rough? With the compression test numbers off that much, I’m surprised you don’t feel a bit of vibration. How many miles are on the truck? Is yer MPG down? No other symptoms but what seems like it is probably a lifter noise? Or possibly an exhaust manifold leaking, but I wouldn’t think that would affect your compression test. I don’t think those engines ran the new(er) 4 stroke cycle (the name escapes me at the moment) where the exhaust valves are opened a bit longer to reuse exhaust gases in the combustion process… Hopefully someone knows what I’m talking about…
The low compression numbers also stand out for me and a noise going along with that could indicate lifters that migh be worn and not opening the valves as much as they should be, instead of holding a small amount of oil inside them they ‘leak out’ too fast thus causing the noise you hear. Keep in mind this is pure speculation as I have not heard the noise and don’t really know what’s going on. In addition to that information my friends at Autonerdz ran into an issue with a misfire and noise on that engine once and it turned out to be that the rocker stud was pulling out of the cylinder head causing excess clearance between the valve and rocker.
Please resist the temptation of running thicker oil to resolve the issue if you suspect that it’s a lifter issue especially in the winter as thicker oil will take longer to reach the top of the engine during a cold start up actually accelerating the wear on the engine.
Thank for the advice. I made a video but I shot it on my phone so it isn’t the best. I am going to try and get my hands on a real camera tomorrow.
here is the link. http://youtu.be/1xW9gsQh5cM
I tried to show the gauges to show it is idling around 800 and running at normal operating temp. The jeep does not run rough and as far as I can tell has no loss of power. But sometimes I am getting a missfire, or possibly a transmission slip when the engine is above 3000 rpms. Thanks.
For just a second there it sounded like an ignition voltage leak when you first started shooting under the hood but not so much when you got to the other side of the engine. If you are sure you are using the correct oil then it might be something to do with a collapsed lifter or one that’s not holding oil pressure like it should, it doesn’t sound like bottom end noise which is a good thing as replacing the cam and lifters is a much easier proposition.
Thanks Eric, I think you may be on to something with the ignition voltage. I took it to my mechanic today and he said that I was not getting the correct voltage to the 4th injector and said I had faulty wiring that was causing a misfire. I also had a lot of carbon build up in the engine. He recommended a couple tanks of premium gas.
Honestly premium gas isn’t going to do anything other than lighten your wallet, here is a video to better explain what I’m on about.
http://www.youtube.com/watch?v=8VWEwEveGTQ
If you wish to rid the engine of carbon deposits I’ve found the best method is to use a professional fuel injection cleaning kit, I have one of these and it works better than anything I’ve seen poured into a tank because it hooks directly into the fuel system and the engine will actually run off of the cleaner, you can get an idea about what I’m talking about in this video even though I don’t use it to clean injectors.
http://www.youtube.com/watch?v=fizKtru7RcU
When I was talking about a voltage leak this is what I was referring to.
Thanks Eric. you solved the problem when other mechanics couldn’t. It was a voltage leak. As soon as I heard you say ” fish biting” I knew that what I had. A friend of mine who is an electrician cleaned up my injector wires and we replace the coil rail now it runs great.
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