Rattling valves on acceleration when engine hot.. Techron not helped - PeachParts Mercedes-Benz Forum

86560SEL · #1 05-04-2006, 04:26 PM

When my cars temperature surpasses 80*C, the valves begin rattling on acceleration. Last week, I put a bottle of Techron in it and it did not help at all. I still have the rattle. Today my engine temperature reached 100*C and it was really rattling.

Is my engine just worn out or what? It does NOT leak or burn ANY oil. BTW - it is a 380SE.

Thanks in advance.

gmercoleza · #2 05-04-2006, 04:58 PM

Are you sure it is rattling valves and not combustion pinging? The only heat-dependent noise I can think of that fits your description is combustion pinging. Can you try putting some 93 octane in there to see if it goes away?

lee polowczuk · #3 05-04-2006, 04:59 PM

i think i would park the car and have it checked out..just in case its one of those rare chain issues...

EDIT....oops didn't see the 80 degree mark starting the issue...does sound more like engine ping...perhaps a timing issue.

derryb · #4 05-04-2006, 06:13 PM

Is oil pressure gauge pegging when you accelerate? If not, could be oil pressure (flow to the heads) problem. Like Lee says, could be timing issue, check the timing. Could also be fuel octane, however i always burned regular in my 380 SE with no chatter; try a different brand. How many miles on your timing chain?

kramlavud · #5 05-04-2006, 07:24 PM

I agree with a previous poster, and recommend you try premiun fuel. If the noise stops your pinging noise was pre-ignition, which could severely damage your engine.
regards,
Mark

Strife · #6 05-04-2006, 07:49 PM

It probably is pinging; the gas or timing is marginal, or possibly - possibly - the temperature sensor is bad (low). Pinging is VERY bad. In my experience, aluminum engines and aluminum valve covers tend to soak up pinging noise (cast iron tends to ring), so if you hear it, it's probably worse than it sounds.

86560SEL · #7 05-05-2006, 12:34 AM

Thanks for all of the replies......

I will first try that premium fuel. When regular is $2.70, I suppose $3.00 for premium does not make much difference huh?

DerryB - yeah, the oil pressure is "pegging" when I get to about 1800 RPMs when the engine is above 80*C. The higher the engine temperature, the higher the RPMs before it gets to "3", but always at "3" by 2000 rpms, even when the engine temperature is at 100*C. When engine temperature is between 60*-80*C, it pegs at "3" at about 1200 RPMS. Even with the gauge at "3" it still pings *IF* engine temperature is above 90*C. I drove it again this evening and temp only went to 80*C and no pinging occured. I must also say that I am not comfortable with the engine temperature going to 100*C (which it does in city driving when outdoor temperatures are above 80*F, but one thing at a time I suppose. Summer is coming and 85* days are very commonplace here. I am also dealing with the stalling issue now when the engine reaches those temperatures.

Miles on the timing chains? Who knows but the car and the original owner, wherever they are. I bought this car from the second owner who bought it in 2000 when it had 199K miles. He bought it from an auction, because the original owners had traded the car in and the lot sold it at auction, so he never personally talked to the owners. He drove the car up to 263K miles and told me had had never put in a timing chain, etc. He said all he had ever done was a fuel pump in 2002. The car now has 266K and I suspect that the chains, tensioner, etc. have been changed at least once, or would have been gone by 266K? I do not know how long the chain/tensioner/rails/guides typically last on these cars.

I have only been driving the car on my days off and going about 3 trips per day in it on those days, but I am thinking of using it less and only driving it to and from work- about 14 miles per day. I think the car should last a couple of years with no more driving than that.

Strife.... what do you mean about the temperature sensors? This could cause pinging? Hearing that the pinging is very bad and damaging is disturbing. I hope my car is not self destructing.

Strife · #8 05-05-2006, 12:52 AM

What I mean, is maybe the engine is hotter than you think, the gauge may be off. I don't think 100C is normal. I'd check that you have the right mix of antifreeze and then replace the thermostat.

PS: How are the fan/water pump/ps belts?

I think 266K on the timing parts is really pushing it. At the very least, I'd change the tensioner and (at least) the upper guides. The spring in my tensioner was noticeably weaker than a new one at 85K. A worn chain will affect timing.

Ferdman · #9 05-05-2006, 06:30 AM

Have a MB-trained tech evaluate the condition of your timing chain, guides and tensioner; otherwise you may end up trashing the engine before 2 years goes by. Speculating on what preventive maintenance was performed by the previous owners is not a good idea.

86560SEL · #10 05-05-2006, 08:54 PM

Oh my ! I did not know that the original chain/tensioner would even last 266K. I was assuming (I know- its not safe to assume) that it had been changed.

Anyway, I know I have the non-recommended green coolant, so it probably be wise to put in the proper coolant.... that could be the engine temperature issue. Thermostat may be another possibility, because in the winter, the needle would go down to about 55*C on the highway.

The belts seem to be in perfect order. As mentioned before, the fan "roars" as if it is working very well when the engine is cold when I first start out, but after that, I cannot hear it whirring anymore.

I was thinking that since it has 266K, that it would be a certainty that it (chains/tensioner) had been changed. I did not know that they would last that long, as I mentioned above.

Ferdman..... how do they check these without taking it apart. Seems like if they have to take it apart to find out, then they might as well go ahead and replace. ? Its just that this car is so old, that I do not want to put alot of $$$ into it. It still runs good and the transmission still performs flawlessly, also, everything still works perfectly with the electrical system and the body is still good and interior excellent, so I hate to junk the car now. Perhaps I could just drive it until the engine conks out, then I part it out?

Thanks.

Quote:

Originally Posted by Strife

What I mean, is maybe the engine is hotter than you think, the gauge may be off. I don't think 100C is normal. I'd check that you have the right mix of antifreeze and then replace the thermostats.

PS: How are the fan/water pump/ps belts?

I think 266K on the timing part is really pushing it. At the very least, I'd change the tensioners and (at least) the upper guides. The spring in my tensioner was noticeably weaker than a new one at 85K. A worn chain will affect timing.

Hatterasguy · #11 05-05-2006, 11:19 PM

Just drive it till it blows and part it.

btw 93 octane is all that whould be going into the tank. I can't think of one MB off the top of my head that spec's regular.

Strife · #12 05-05-2006, 11:32 PM

55 degrees C - I think that the thermostat is stuck open.

86560SEL · #13 05-05-2006, 11:33 PM

Yeah, for as little as I paid for it, that is what I was thinking.....

I was told that 1985 and older Mercedes did not require premium fuel, but I have no clue. I do know that the instrument cluster does not say "premium fuel". Not sure what the owners manual states.... I guess I could check that out, as that usually tells what fuel to use.

Thanks.

86560SEL · #14 05-05-2006, 11:34 PM

Yeah, that is where it stayed at when I was on the freeway, in the winter when outdoor temperatures were below 50*F. When I was in town, it would go up to 75*C-80*C, but always back down with speed.

Thanks.

Quote:

Originally Posted by Strife

55 degrees C - I think that the thermostat is stuck open.

t walgamuth · #15 05-06-2006, 06:47 AM

Quote:

Originally Posted by Strife

55 degrees C - I think that the thermostat is stuck open.

better get it changed. the car is designed to run at 80 to 85. cooler is not good for it.

yeah, i am with the guys stating you need to run premium for correct performance. and it could be running hotter than indicated too. running too cool (like you did last winter) will allow buildups of carbon and such in places where it may cause harm.

your car could also be running wo a stat. and if so it will run cold in winter and hot in summer. never the way it should be. bad idea in a benz.

tom w