Low Power, Dies After Revving - Page 5 - PeachParts Mercedes-Benz Forum

GoldenEagle · #61 03-05-2017, 02:14 PM

Quote:

Originally Posted by funola

A quick look at your post history shows you had problems with the alternator, water pump, crank pulley, vacuum pump and probably more. You had screeching or squealing noise from the engine since you acquired the car., then you discovered a red rag inside the valve cover..... that is a big red flag IMO. You said there is no air in fuel per the clear return to tank line- that is good.

Can you post a video of the engine idling, reving and the squeal/ screech? Have you tried to isolate where the squeal/screech is coming from? Is it internal or external (alternator, water pump, AC compressor belt/ bearing) to the engine? Use a wooden broom stick cut to length as a stethoscope and see if you can localize where the squeal is coming from.

Thanks Funola. I really appreciate the work you've done reading up on the history of my car. It's been a saga. I'll do the broomstick trick today and post a video.

GoldenEagle · #62 03-05-2017, 10:50 PM

Car was running worse than ever today. It would only stay running if I kept the pedal completely pushed down, which made it very difficult to get a video. It was making all kinds of terrible noises and would die immediately when I let of the pedal. Video below is the best I could do by shooting through the crack under the hood while standing on the pedal. You can hear the squeaking very clearly. It was not shaking and knocking until today. Starting to think this motor is beyond repair...

https://youtu.be/VJQF9tB938A

Diseasel300 · #63 03-05-2017, 11:23 PM

Sounds an awful lot like a seizing bearing + knocking rod to me. A bit of deja-vu from the first thread you posted with the squealing and finding the rag shredded in the valve train

kerry · #64 03-06-2017, 10:57 AM

I'm not sure that's a rod knock. It comes and goes. I don't see how a rod knock could come and go. But something's seriously off with that engine.

kerry · #65 03-06-2017, 10:59 AM

Timing chain slap?

kerry · #66 03-06-2017, 11:00 AM

Maybe the timing chain has jumped some teeth?

kerry · #67 03-06-2017, 12:00 PM

It sounds too tinny for a rod knock.

GoldenEagle · #68 03-06-2017, 12:12 PM

Quote:

Originally Posted by kerry

Maybe the timing chain has jumped some teeth?

I had the valve cover off about a week ago to check this and the timing marks on the cam and on the crank balancer aligned perfectly at top dead center.

kerry · #69 03-06-2017, 12:27 PM

Has something happened in the meantime to produce the current symptoms?

GoldenEagle · #70 03-06-2017, 12:34 PM

Quote:

Originally Posted by kerry

Has something happened in the meantime to produce the current symptoms?

Up until yesterday, it would at least idle while cold and drive (very slowly) and was only making that intermittent squeaking noise you heard on the video. Once it got hot, it would die. Then yesterday I tried to get it to start and was getting what you saw in the video. It would only idle if I stood on the pedal and even then it was idling very roughly and making all those terrible noises.

kerry · #71 03-06-2017, 12:39 PM

I can't think of what else would be making that sound apart from the timing chain.

GoldenEagle · #72 03-06-2017, 12:40 PM

Quote:

Originally Posted by kerry

I can't think of what else would be making that sound apart from the timing chain.

Is there any other way to check it besides the timing mark alignment check that I mentioned? There doesn't seem to be any obvious slack in it that I can feel by hand.

BWhitmore · #73 03-06-2017, 01:01 PM

The fairly light mechanical slapping noise does not sound like a rod knock. I also believe it is coming from the timing chain/valve train area based on the timing of the noise. A timing chain problem would also explain the loss of acceleration/no power situation. If I remember your original post with the rag, I believe the picture shied the rag wrapped around the front of the cam/timing chain which could have resulted in the chain jumping some teeth on the cam sprocket.

jake12tech · #74 03-06-2017, 02:46 PM

Timing is severely off (jumped a few teeth) or valve train.. What did you in was the rag wrapped around the cam. That motor is fixable with some top end work. Don't run it anymore after that video at all or you could do serious damage. If it is the chain, and it breaks you're gonna bend a bunch of valves. That sound isn't a rod knock like others said, they don't come and go. They're consistent and have a deeper metallic sound. It's only a video, and I'm no there in person but that's top end noise, not bottom end. Loss of power, stalling all points to a timing issue or valve issue... Also, remember metal expands with heat... It probably just got worse this this time around.

funola · #75 03-06-2017, 03:07 PM

Quote:

Originally Posted by kerry

Maybe the timing chain has jumped some teeth?

I see this statement a lot. In reality, it is just about impossible for a double row timing chain to jump a tooth. Next time you adjust the valves, look at the timing chain and how it is mated to the sprocket and you will come to the conclusion it is nearly impossible to jump a tooth.

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