E220 serious oil pressure loss

[nmacc]

Hi Folks,

I've a 93 220TE with 185k. Made a 100 mile trip this weekend and noticed upon arrival at my destination that power seemed to have dropped slightly. Also noticed a strange rasping sound at > 3,000 rpm, rather like top-end noise, or (heaven forbid) a broken ring.

When I began the return trip I noticed that the rasping sound was becoming audible at lower revs. After about 15 miles the oil pressure seemed to drop slightly. When I slowed down it dropped away completely to zero, but the oil light did not come on.

Finally made it home at a steady 55, but the rasping noise is much more evident and oil pressure at idle reads zero, rising to just short of 3 Bar at 2,000 rpm.

At all times engine temperature has been low-medium and oil and coolant levels are fine. I can't detect any sign of bottom end rumble and she's not buring any oil.

Any thoughts?

 

[grober]

First thing to check is the V BELT TENSIONER and its shock absorber bushes. The bearing on the tensioner wheel can fail. While you have the poly V belt off check all the other pulley bearings- water pump, alternator, power steering, air con -- for wear/roughness/noise Otherwise sounds as if it might be valve train related. A problem with the timing chain tensioner or chain guides ( maybe one has broken) The other possibility is some sort of malfunction with the inlet camshaft advance mechanism. You need to get the cam cover off and have a good look. I would try not run the engine till you have located the problem unless briefly with the bonnet up to try to locate the source of the noise--don't catch your fingers in any of those rotating parts.
P.S. You can expect the oil pressure to drop at idle when the oil is hot.

 

[nmacc]

Thanks Grober,

You may have a point about the belt tensioner, there has been some bearing noise for a while, but I don't think that's the source of my most serious problems.

When I said the oil pressure dropped - I meant that it disappears!

I'm familiar with the oil pressure behavior of these beasts when hot, but this is different: it's both extreme and sudden. Yesterday I had normal oil pressure; today I have virtually none.

Regards,

Niall

 

[grober]

Fair do's There is a separate chain drive to the oil pump also with a tensioner- I guess there might be a problem there?? http://www.detali.ru/cat/oem_mb2.as...GM=717.413&CT=M&cat=19K&SID=18&SGR=015&SGN=01

 

[nmacc]

Thanks for the drawing Grober, that looks like a possibility.

I've now had a chance to look at it in the cold light of day and she's losing oil from around the area of the main crank seal. She's always had a weep from the crank seal, but it wasn't really worth worrying about as it didn't even spot the driveway, provided I wiped it down once every few weeks.

Bit more extensive this morning; not a puddle, but there are some large spots that have appeared in the past 10 hours.

 

[nmacc]

The bad news

Thanks for the advice on this folks, but the bad news is that it's been diagnosed by an MB Specialist......

It's a big end.

Looks like 220TE RIP. Particularly irritating as I'd put a lot of new bits on this one as I was planning to keep her.

 

[grober]

I have to say I'm surprised since the bottom end of these is pretty indestructible unless it's have been starved of oil. Second hand engine a possibility?

 

[nmacc]

I'm digging around for a used lump at the moment Graeme. They seem a bit thin on the ground, but I suppoe they're like buses; you wait weeks for on and then 3 come along at once. I'm also on the lookout for a tame Polish mechanic who's willing to work for some table scraps and a tarpaulin to sleep under in the garden - a bit like my wages!

It might be practical to change the big end in situ.

Niall

 

[grober]

I'm digging around for a used lump at the moment Graeme. They seem a bit thin on the ground, but I suppoe they're like buses; you wait weeks for on and then 3 come along at once. I'm also on the lookout for a tame Polish mechanic who's willing to work for some table scraps and a tarpaulin to sleep under in the garden - a bit like my wages!

It might be practical to change the big end in situ.

Niall

Tempting tho replacing one bearing shell might be I would be wondering why it failed in the first place. I would be suspicious of the oil pump or its drive or a partially blocked inlet?

 

[Dieselman]

If a big end has gone the crank may well be scored beyond reasonable repair.

 

[lynall]

Years ago 16ltr gardner engine picked up big end new shells crank cleaned up did it again scrapped truck well it was an ERF what do you expect?


Lynall