I got an oil report back today that has some cause for concern:

"At 234,801 miles wear from your OM 603 continues to look good. Unfortunately we found quite a bit of fuel dilution in this sample. 4.0% is well into our cautionary range and may indicate a fuel system problem developing. As we've never seen this much fuel in one of your samples we're hesitant to make that call just yet. We'll know more with the next sample. No coolant or moisture was found. Both silicon and insolubles read normally showing good air and oil filtration. We suggest resampling in another 3,000 miles to monitor fuel dilution"

On the previous test (3,015 miles before) I had a trace of fuel, not in the cautionary range (which is at >2.0). What should I be worried about? Should I just sit tight as they suggest or is there something I should look out for in particular?

Also had a slight increase in potassium that I don't like, although they didn't mention it as a problem. Jumped up from to 11 from 9 on the last test (univ. avg. is 8) ... guess I'll watch that too ... damn, these have come out real well for the past several oil changes ... this is a week I could have used some good news ...

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

How does the engine run? Might be an injector or injection pump issue....

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Do you do a lot of short trips?

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

there are only two ways for fuel to mix the crankcase oil. one lift pump going bad. and two injection pump elements worn out.

__________________
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

pawo: Engine runs beautifully. If not for the report I wouldn't have a concern ... sounds smooth, very peppy.

Hattie: Yes, I do a lot of pretty short trips. Recently I've been looking at houses so I've done a lot of bouncing around neighborhoods and stopping and starting.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Being a real estate agent, I do a ton of short trips. But I drive a lot as well so I burn off whatever accumulates. Now when I know I'm just going to run in I leave it running.


Have you ever done your injectors? It not pull then and have your local Bosch shop test them and fix the problem ones. Its a very simple job that if the injectors are original will yield good results.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

What is the magnitude of repairing either of those problems? Given the car's solid performance at the moment I don't see this as a panic situation, but I'm worried nonetheless and want to prepare for it if this is a major problem ... yikes ...

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

LIft pump is fairly easy its on the side of the injection pump it runs off a small cam in the IP. so i think its two bolts and it comes off. now as for the elements... thats major work and i would suggest getting it sent off to be worked on unless you really really know what your doing.

__________________
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

How would having injectors tested and calibrated have any effect whatsoever on fuel dilution??

If they are all pissing you wouldn't get a complete burn, throw in short trips and you have some fuel in the oil.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

..........where's the white smoke..........where's the poor idle..........where's any symptoms of "pissing injectors"?

Well whats the problem then?

Lift pump? IP? Only so many ways fuel can get into the oil.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

You might get 4% fuel dilution from injectors..........but, I seriously doubt it. It would require a bunch of very short trips in cold weather. There would be some symptoms of incomplete fuel combustion.

I'd go another 3K and check the oil again. If the fuel dilution drops down.......it's an anomaly due to injectors...........if it climbs to 6% or higher, it's the IP or the pump.

Thanks for the input guys. I appreciate it. I'll keep an eye out for symptoms of injector problems. I get a little white smoke on startup, but I cna't recall a time that I didn't get a little white smoke on cold startups in November. And like I said, runs like a champ and idles smoothly.

As I wait out the next 3K, is there anything I should look out for that would hint toward either the lift pump or more significant IP failure? Will further degradation of those elements create performance problems that will give me a better clue?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Just drive it..........there's no way to determine the culprit without removal and inspection. I'd be more inclined to think it was the lift pump unless its an anomaly.