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.

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2004 Toyota Sequoia Limited 4wd
1991 Lincoln Town Car Executive
1991 Cadillac Sedan DeVille
1988 Mercedes 300SEL
1972 Chevrolet Caprice Kingswood Estate 9-passenger wagon
1973 Pontiac Grand Ville
(Prior MB's: 1974 240D, 1985 380SE, 1984 190D, 1993 400SEL)

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?

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

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.

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

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?

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65 190d sold
85 380SE sold
87 560 SL 180K
84 380SE 96K (mint)

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

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.

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86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm

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.

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.

__________________
86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm