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engatwork 11-22-2020 08:03 AM

272 engine oil leak
 
I've got an 08 E350 in the shop with a bad oil leak. I've replaced the breather puck on the rear of the passenger side valve cover and the plugs. Seems to be a substantial amount of oil sitting in valley of the v of the engine. Before I remove intake manifold what is under there on this application that could be leaking oil. Thanks

paul roberts 11-22-2020 08:06 PM

Quote:

Originally Posted by engatwork (Post 4115345)
I've got an 08 E350 in the shop with a bad oil leak. I've replaced the breather puck on the rear of the passenger side valve cover and the plugs. Seems to be a substantial amount of oil sitting in valley of the v of the engine. Before I remove intake manifold what is under there on this application that could be leaking oil. Thanks

I've done more than a handful of the vacuum pumps on the back of the engine on the driver's side for leaking oil.

engatwork 11-24-2020 06:00 AM

I'm not seeing any leakage from anything attached to the back of the heads/valve covers but the v below the intake seems to be full of oil. I'll get around to investigating it further over next few days.

engatwork 11-24-2020 06:56 PM

Got it on the lift this evening and based on all I can see it looks like the lower oil pan and oil fill cap are leaking. Will change both over next day or so.

engatwork 12-01-2020 07:23 PM

Looks like new oil cap fixed it. This is not the first time I've seen a new oil cap fix a leak this year model.

RobertFini 04-26-2022 11:16 PM

'07 E350T-4M Massive Oil Loss
 
Quote:

Originally Posted by engatwork (Post 4118644)
Looks like new oil cap fixed it. This is not the first time I've seen a new oil cap fix a leak this year model.

Hey, Jim!

My wife's 2007 E350T-4M with M272 has very suddenly begun losing massive amounts of oil (three quarts in 275 miles); some is burning, as I see a thicker cloud than I should on startup that dissipates pretty quickly, but there's a massive leak as well, with oil up on top of the engine near the front, which could be the filler cap as you found in your case.

I've had the car to two different indy shops and neither wants to take the time to figure out the problem, just telling me it needs a new engine. After practically begging the second shop to do a compression test, they tell me all six cylinders are at 150 psi, but are claiming that doesn't confirm anything, as it could be the compression rings are fine but the oil rings are shot. Their theory is that it's blowby pushing oil out the dipstick, but I don't see oil on the dipstick tube and if the compression is good I wouldn't think there should be much blowby. There is also a very ugly cyclical noise from somewhere in the engine compartment that they've diagnosed as a piston slap, but I can't say that I've ever heard a piston slap and don't know whether to agree or disagree with them.

Any thoughts on the subject would be welcome.

Best Regards,
Rob

Sugar Bear 04-26-2022 11:36 PM

Rob,

What has been the historical oil change interval on this engine? What type of oil has been used e.g., synthetic, MBZ approved? Is it used for mostly short trips or highway?

My GUESS is clogged oil control piston rings. Other than a good used engine I'd try a couple of motor flushes with Liqui Moly engine flush.

Good luck!!!

Zulfiqar 04-27-2022 06:33 PM

Quote:

Originally Posted by engatwork (Post 4118644)
Looks like new oil cap fixed it. This is not the first time I've seen a new oil cap fix a leak this year model.

I saw the same on some 273 engines too, One was a dealer maintained car which "needed an engine" because it was too oily outside.

which came to be a split oil cap gasket :facepalm:

some shenanigans are just too much - and I specially see that with original owners of S class cars like this one was.

Zulfiqar 04-27-2022 06:35 PM

Quote:

Originally Posted by Sugar Bear (Post 4229829)
Rob,

What has been the historical oil change interval on this engine? What type of oil has been used e.g., synthetic, MBZ approved? Is it used for mostly short trips or highway?

My GUESS is clogged oil control piston rings. Other than a good used engine I'd try a couple of motor flushes with Liqui Moly engine flush.

Good luck!!!

clogged oil control rings would be quite a show on a mercedes benz M272 as the rest will have packed up way before that. (the cylinder heads and variable cam timing dont like bad oil)

RobertFini 04-27-2022 06:42 PM

Quote:

Originally Posted by Sugar Bear (Post 4229829)
Rob,

What has been the historical oil change interval on this engine? What type of oil has been used e.g., synthetic, MBZ approved? Is it used for mostly short trips or highway?

Always followed the FSS notifications, with services done at reputable shops using approved OEM supplies, which for this car would be full synthetic; most of the miles have been open highway here in the northeast US, but it's seen its share of city driving, too.

Volvo Diesel 04-28-2022 09:40 AM

Rob,

You might want to read through this thread from "that other site." https://www.benzworld.org/threads/2004-e320-oil-consumption.1694417/#post-5620892

If you read through to the end, you'll see that OP had eventual success with the "procedure" discussed in the thread and switching to a 5W-40 oil (often the independent shops fill with 0W-40). I'll note that the OP in the thread had the M112 V-6 as opposed to the M272 V-6 in yours, but there have been other posts over the years on that site discussing using the same procedure and switch to 5W-40 for the M272. I was too lazy to search in more detail, honestly.

Also, I'm sure you know this already, but these motors can lose a lot of oil due to leaking cam plugs and a leaking crankcase breather/oil separator.

Anyway, I'm not saying the procedure discussed in the thread will work for you, and I've no experience trying it, but it seems to have helped some folks. I haven't had the oil consumption issue with my E350 wagon with the M272; it has about 150,000 miles on it now. I've never followed the FSS notifications since I bought it in 2008; 12,000 miles/1-year seems like an awful long time to me. I just do the oil and filter every 6 months, regardless of mileage. Yes, I'm probably wasting money doing so, but it's an easy schedule to stick with.

I hope you're able to solve the issue without having to spend a lot or replace the car. Best of luck.

-Chris

RobertFini 05-07-2022 01:21 PM

Quote:

Originally Posted by Volvo Diesel (Post 4229969)
Rob,

You might want to read through this thread from "that other site." https://www.benzworld.org/threads/2004-e320-oil-consumption.1694417/#post-5620892

If you read through to the end, you'll see that OP had eventual success with the "procedure" discussed in the thread and switching to a 5W-40 oil (often the independent shops fill with 0W-40). I'll note that the OP in the thread had the M112 V-6 as opposed to the M272 V-6 in yours, but there have been other posts over the years on that site discussing using the same procedure and switch to 5W-40 for the M272. I was too lazy to search in more detail, honestly.

Also, I'm sure you know this already, but these motors can lose a lot of oil due to leaking cam plugs and a leaking crankcase breather/oil separator.

Anyway, I'm not saying the procedure discussed in the thread will work for you, and I've no experience trying it, but it seems to have helped some folks. I haven't had the oil consumption issue with my E350 wagon with the M272; it has about 150,000 miles on it now. I've never followed the FSS notifications since I bought it in 2008; 12,000 miles/1-year seems like an awful long time to me. I just do the oil and filter every 6 months, regardless of mileage. Yes, I'm probably wasting money doing so, but it's an easy schedule to stick with.

I hope you're able to solve the issue without having to spend a lot or replace the car. Best of luck.

-Chris

Thanks for your thorough response, Chris; I'm sorry I've been incommunicado for so long and wanted to get back to you.

I read through that thread to which you linked and I'm just not a believer in the "Italian tune-up" method, and while there is a significant amount of smoke due to oil burning, I would say that most of the loss is due to leakage, with the leak being so egregious at this point that I doubt there'd be anything left in the crankcase by the time I'm finished with the procedure.

I checked our service receipts and found that our indy shop has been putting in 5W-40 since at least June of 2020, along with an oil treatment additive from BG called RF-7 (https://www.bgprod.com/catalog/engine/bg-rf-7-oil-treatment/), which doesn't look like it should cause any harm and might actually do something helpful by increasing viscosity.

We've replaced the centrifuge (Mercedes-speak for the separator) at least twice, as it seems to be a regular point of failure, and checked the cam plugs, but the oil is all over the front of the engine and those bits are at the rear. I will replace the oil filler cap, despite it not looking terrible, and see what effect that might have.

Best Regards,
Rob

Volvo Diesel 05-08-2022 03:56 PM

Quote:

Originally Posted by RobertFini (Post 4231141)
. . . but the oil is all over the front of the engine and those bits are at the rear. I will replace the oil filler cap, despite it not looking terrible, and see what effect that might have.

If the oil leak is on the front of the motor, and the oil cap doesn't make a big difference, you may want to look at the oil filter housing. On my M272 that started leaking pretty badly, enough to make a mess down the front of the motor and in the belly pan under the car. The shop that diagnosed mine changed out the housing because the housing had a crack in it. I believe they said sometimes you can just replace the gasket. The housing wasn't too expensive but I imagine it's even cheaper if all you have to replace is the gasket. I want to say they mentioned changing out another seal as well during the repair (oil cooler, maybe?) but I can't say for sure; it was back in 2013 and they didn't write it down on the receipt, it was presented to me as kind of a "while we did this we also threw in this" type of thing.

Good luck!
-Chris

RobertFini 09-24-2022 07:15 PM

My apologies to all for taking so long to update this thread; the car is located at our vacation house in the Hudson Valley and I haven't been able to spend much time with it this Summer.

Nevertheless, I'm here now and I suspect that the problem was an improperly fitted oil filler cap. The last time I was here (about two months ago), I took the car for a high-revving ride on the Taconic Parkway 20 minutes out and 20 minutes back, holding it in third gear with the cruise set at 64 MPH, so running just under 4K RPM the whole time, and the only smoke we had was at initial startup (but lots of it). During the ride, the low oil indicator came on, but that was to be expected.

This time I added two quarts of oil and did the same thing, and got the same results - plenty of oil smoke on initial startup but then nothing when I went out on the highway at sustained high revs. When my wife initially had the problem, we had just had the car serviced back home but she reported no issues on the four-hour ride up; however, we did have the car inspected after she arrived (it's registered in NY and was overdue), so I suspect they topped off the oil and didn't replace the cap properly.

Thank you all for your input and feedback on this. If I recall correctly, oil smoke on startup is indicative of bad valve seals, right?

Best Regards,
Rob

engatwork 09-25-2022 07:34 AM

Sitting at a red light idling and then accelerating away, with smoke coming out of tail pipe, is indicative of valve guide seals based on what I've read.


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