Could using the wrong oil (non C rated) have ruined my 240 engine?
 

I loaned my 240 to a friend a couple months ago. He returned it after logging about 3,000 miles on it. It has been sitting for a month or so because I could not get the engine started. I tried several things again today, and still no start. I had the block and lower rad hose heaters plugged in for about 6 hours, and the battery charging. I also put a blow drier on high connected to the air intake hose. It sounds like it wants to start, and even smells like partially burnt fuel. I changed all the glow plugs the other day as well. I found a half used quart of 10W-40 oil in the trunk. It was regular gasoline (S rated) oil. I knew the car did burn oil, so my friend had to have added some during the 3,000+ mile trip. Could using the wrong oil cause damage to the engine? The other possibility is that he could have ran it out of oil. I don't know for sure. I guess I need to do a compression check next......Rich

VERY unlikely...

Oh, _NO_
 

I hope he didn't run it out of oil, I've seen that occur so many times over the decades .

Do the compression test. Extremely unlikely the oil caused the problem. Lack of oil could cause the problem. Ask him if it ran out of oil.

Exactly...the oil isn't a problem. Running out of oil could be. Is the glow system actually working? Air purged from injector circuit?

Did you see the car drive in when returned / did you start car soon after it was returned?

Any idea if he used Bio / veg or other non standard diesel?

Wrong type of oil: Not a problem even if filled with gas oil in the short term. ( As in 10's of K miles )

How many miles does this car get per Qt and under what conditions? ( round town sub 40 MPH will use less oil per mile due to low loads , highway 60 + will use more due to higher speeds / loads. ) How many OT does this car hold?

No start due to out of oil: If the engine is cranking at normal speed, not an oil problem. The first parts of an engine to suffer oiling deficiency / locking up will be the connecting rod bearings, next will be main bearings. Pistons / rings / valve train won't going to be a problem.

The car did drive when it was returned. However, it was warm when I drove it to my other place (1/2 mile). I went to start it a few days later, and it took a good 10 minutes to get it to run. It would "run" with the starter engaged, but soon as I let off the key from the start position, it would die. I finally got it to run enough on it's own to get it where I could work on it. I ran it on veg years ago when I got it, but have only had Diesel in it for the last year or so. He only put D in it the entire trip. I only drove it once or twice a week around town, so it didn't use much oil. I think I had to put a quart in every few months. I will ask how many quarts were used for the trip. His trip was all highway, and some of it pulling an empty motorcycle trailer (maybe 300 pounds?). I definitely need to do a compression check. A bummer though, I just changed the glow plugs after it took the 10 minutes to get running. I could (should) have checked the compression then, it would have been easy.

Maybe I missed it, but have you checked for a fuel restriction?

Agree. Sounds like not enough fuel getting through. Or maybe he got some bad fuel at his last fillup.

I know for sure it is getting fuel. The filters were changed sometime during the trip. I don't know about bad fuel, but I suppose I could isolate the fuel intake in a fresh can of fuel and try to start it. I will do a compression test first. If that is inconclusive, I will look at the fuel system.

Smell the filler neck for any gasoline smell. Of course it could have been a tank of gas long gone now. It may have gotten really hot and taken the temper out of the compression rings at some point. Could he have lost coolant and there is no red overheating light?

Today in general a lots of people do not check their oil regularily. I am guilty of this on much newer cars Myself. If your friend ran low on oil it could be expected today with a 240d rolling up the miles. As for the wrong type oil as mentioned. If anything tens of thousands of miles. to make any noticeable difference. Even then it would not be this extreme.

Your problem sounds more consistant with something else though in my opinion. The compression check is needed unfortunatly. There is a chance that it is fuel supply related. Just so much easier to start with the compression check first. Watch and record your numbers carefully. They may provide a clue as well as a general result. For example if it was a tank of gas the injectors may be your issue. You will have useable compression. Actually I am hoping that is a probability. Simply because I am cheap probably. The quickest test I can think of is with a friend. Get them to glow the engine. You spray wd 40 into the intake. If it lights off pretty well instantly. Compression is probably not your issue. Also from your description it has remained pretty cold since the car came back. Is there any chance at all you just have a gelled fuel situation. Starts and runs as long as the starter remains engaged does indicate something. Like severe under fuelling may be an issue. Or not enough cylinders on line to sustain running.

Personally I try to borrow almost nothing except in some form of emergency. Simply because if it breaks while in my possession I feel obligated to fix it even if it was not my fault but just the time for it to fail.

I really always have had a policy of trying to help out the next guy. There is an element of truth in you get what you give. Then the era of few returning what they borrowed became an issue. Without me having to chase them for whatever.

What I found changed with others as well. Yet I still can borrow something as needed on rare occasions. Simply because they know it will be returned when I say it will.

It takes a lot to get me going but one of the son in laws never and I mean never returns anything borrowed without a chase. In some cases I have even had to go out and buy the tool again. Last item was my twenty five ton hydraulic jack. Somebody took it on him apparently.

If it is in the family you have to absorb the good with the bad though to keep peace. In this case relatively minor in the overall condition between relatives. Compared to many other situations that people have to deal with inside their own families sometimes. Actually insignifigent in comparison. I am just thankful that this is the worse in our family so far from my perspective. In personal relationships. Between myself and the four son in laws.

I only touch upon this as a consideration with your friend as a continuing relationship. You have to know that if he created this issue he did not do so intentionally.

I notice the wife gets a little disturbed with some member of the overall families actions from time to time but also suppresses it well. She is cognizant that all four of the son in laws could easily be a lot worse. Actually by guy standards they are pretty good. Women do not always see things quite as we do might be considered. To put it mildly.

I think the thread would be a lot more interesting. If you had loaned the car to a really hot chick. Then we could discuss issues of why you did not check her oil regularily etc. Or how lucky you got off this easy.

Anyone that even bothers to read my long running wandering posts deserves at least a little levity. I really should get back to dealing with my own long list of things that need attention.

Don't even have to do that. Just make a homemade fuel tank under the hood next to the injection pump using a milk jug with fresh diesel. Put both fuel lines in there, prime the system and crank.

Could using the wrong oil (non C rated) have ruined my 240 engine?

NO

Look at the plastic fuel filter and see if you can see any dark crap inside of the filter. If so you got some bad fuel (on your friends trip?) and something is growing inside of the tank or contaminated the fuel.

You might also check to see if the strip fuse on the glow plug relay is not cracked or burned and use an ohm meter to check the glow plugs.


New does not always men good. I have had new dead spark plugs and one dead new glow plug.
If the new Glow Plugs were autolites or monarks they don't last long.

What caused the filters to need to be changed during the trip?

Since I had only driven the car around town, and never more than 20 miles or so at a time since I owned the car (it is just a "beater with a heater"), he changed them on the road because they got clogged from running so much fuel through the system. I checked today, and the fuel in the pre-filter looks fine. The new style primer pump works good as well.



I pulled the glow plugs today and did a compression check. The results:


(1) 250
(2) 240
(3) 320
(4) 100


I now know what the problem is. I even did #4 over again, and it still only got up to 100. I could see a mist of fuel coming out of the other glow plug holes when cranking, so I know it is getting fuel.
I got my pump oiler, and pumped about a pint of MMO in each cylinder. I will probably do another round tomorrow, and may even pump a bunch in #4 before putting in the glow plug and soon after trying to start it. If all else fails, I will sell it as-is or part it out.......Rich

my first line of thinking would be to hook up some fresh fuel with fresh filters in a bottle and try and run it off that after priming the system. That way you can easily trouble shoot the fuel tank, fuel IN the tank, and any of the lines.

EDIT never mind, just read your response! sorry to hear that ;(

Yea, since I saw fuel mist exiting the other three cylinders, I pretty much knew it does not have a fuel problem.

that’s awful. I hate it when people do this to me. My wife borrows my 300sd and it always comes back with something broken. I love her but that is pushing it! :D

For what it’s worth, I drove my 240D with over 300k for 2 years on used motor oil from my wife’s Honda. I knew the car was going to get donated so I figured heck, just top it off with old oil. One quart a week. It leaked but had great compression. Long story but I had to dump the aging car due to a move to the hill country and too many worn parts. But that engine just took it. It started and ran well till they drove it away. Shame.

Not an oil problem if it was not knocking since it ran after being returned.

This is a fuel delivery / starvation issue. Unless it is locking up and barely turns, the entire engine won't suddenly suffer all injectors failing or all piston rings failing or all intake / exhaust valves not sealing.

My 70's International backhoe ( with a German built Neuss engine ) was run at 1/4 or lower tank before I bought it and for a while I did the same. For a big job I filled it full. Soon after ( like at 1/4 tank ) It started clogging fuel filters that were a few hours old ( RE when I was running at 1/4 tank ).\

With a full tank, sludge was washed off the area above 1/4 tank. I'm betting that you usually ran the car with less that a full tank and the recent guy filled up.

So the engine is running now?

Do a leak down test before going any farther, we need to see where the compression leak is.

What was the compression in the past? It is sounding that the engine was pretty worn out before your guy used it.

I do have a leak down tester, so yes, that is next. I have never checked the compression before today. It usually started without issue in the three seasons other than winter. It did start in winter using the block heater and glowing at least two cycles.

Just sounds like a tired engine to me. If a diesel has a hard time starting in cold it has poor compression or bad glow plugs. The trip and hauling the trailer might have accelerated the wear even more.

The more I think about it, I tend to agree with you. However, why would one cylinder be so much lower than the rest?

Perform the leak down test - you don't know if it is a top end or bottom end issue yet. There are a lot of possible reasons for poor compression - a single bent valve would only affect one cylinder, for example.

Sometimes some cylinders wear more than others. I’ve seen some cylinders fail completely or have significantly lower compression than the rest.

Here is an example of an engine that allegedly had 300+ psi on cylinders 2-5 and 0 psi on cylinder 1.

https://i.imgur.com/fxUqndD.jpg

I'm with Jake12 on this. Performing the leak down test is a waste of time. If only one or two adjacent cylinders were low then it would be useful. All four low? Fuggedaboudit! Source another engine and move on.

A leak down test doesn't take very long. Diagnose, don't guess.

Reminds me of when I loaned a nice (almost NEW) 2stroke leaf blower to a neighbor (along with some gas). He ran it all afternoon, used up the fuel we provided, then ran a full tank (or two) of gas with no oil mix through it. Engine was toast. Hands it back saying "it stopped running".

:glare:

It was then I essentially swore off loaning people most things...especially cars or power tools. (I do make a few exceptions for specific friends or family who treat tools/things nicely)

Before Giving Up.....
 

Do the leak down test ~ if the valves are the problem, do a valve job and it'll prolly last another decade .

If it's the rings set it aside and see if a good used engine doesn't turn up ere long .

My '82 240D's #1 exhaust valve got to zero clearance, I couldn't adjust it at all, drove it like that for well over 20,000 miles including a *very* slow cross country trip of three weeks , it never missed a beat although on some remote mountain roads with *really* steep grades it would barely make walking speed .

Unless the car is trash it's worth saving and you have the skillset .

Anyone whi under stands a leak down test, will do one ~ only those who are not Mechanics of any sort will say waste of time .

Why would you perform a leak down test on a worn out engine? It’s worn out you already know it has low compression. If you have intentions of doing a rebuild maybe. It’ll tell you how good of a seal the rings are putting out. You said if it’s worn out you’d sell the car for parts. So the leak down is pointless

Leakdown is good for isolating problems to valve, piston clearance or head gasket leaks. Yeah, it sounds like the engine is junk, but pumping up #4 at TDC And listening at the intake, oil filler and exhaust pipe for air loss will tell you if it is something easier than a damaged cylinder.

A bit of a blanket statement there Chief don't you think?

A leak down test is a good diagnostic tool but in this case, what's it going to tell you? That you have a problem with low compression in all four cylinders? If the valves are adjusted properly you have a leakage somewhere? You are still going to have to pull the head for a physical inspection.

Whatever, it's your car, your time and your money.

This is exactly my thought too. If you're only using the leakdown tester to listen for air escaping, why not just blow compressed air in the cylinder? Why bother with fancy tools you're going to use this ONE time on a pointless process? If it were only one cylinder that were wonky on an otherwise good engine, sure. On this one with oil consumption issues on a beater car with low compression in the other 3 holes? Why bother.

I'll +1 the leakdown test before condemning the engine. It's easy to do and yields a huge amount of info.

Because a leakdown will tell you specifically what is wrong with the engine.

A mechanic won't get very far with some customers if you only tell them " the engine is junk ", they are going to ask for an explanation as to what specifically is wrong. If the tech replies with " I told you, the %$@#Q%R#$!@ engine is junk you R$##$$#Q@$. " ,that only shows one does not fully understand the system they are working on.

An engine isn't a monolithic piece of equipment that can't be repaired. If this engine has a broken valve spring, cranking compression could be low. Would you really want to scrap an engine over a valve spring or a valve lash set too tight?

What if there is a burnt valve but the bottom end is good? In this case a valve grind will get the engine going again.

I've rebuilt countless engines at a professional level and have done many of what I call " junkyard rebuilds " that result in that " good used engine " when complete. With cars this old, that good used engine is going to be increasingly difficult to find. With a JY rebuild engine quality is known and it will have good power Vs that unknown engine that may also be nearly worn out.

As for tools to perform a leak down test, all you need is a compression tester adapter with the check valve removed ( most if not all use a tire type valve with a very light spring ) and a source of about 100 PSI air. We don't care so much what % of leak down we have, we care where the air is leaking out of.

Lastly, if one is going to install a used engine, doing a leakdown would be a good idea anyway.

PS A junk yard rebuild consists of using parts on the high end / slightly over max reuse clearance. Remember, the reuse clearance assumes the engine is apart and being rebuilt. The absolute running upper limit is larger than that.

I totally agree. Even if I assume this engine needs major work (and I do), I still would like to know what is the cause of the low compression. Since three of the cylinders are 240# or lower, and I know that the valves are adjusted correctly (they were checked just before lending the car), I am assuming the valves are NOT the problem. Thinking back, I lent the car to another friend in late 2016, and he did not check the oil level then. It always burnt oil since the day I got it. I am suspecting that the rings are collapsed, and that is the problem. Either way, I need to remove the car from my insurance, and either sell it as-is, or fix it (rebuild the engine). I could even sell it to the State (Voluntary Accelerated Vehicle Retirement program) for $1,000 (what I paid for it). The problem is, the car has to run under it's own power. Also, I would like to keep this and all other classic Mercedes-Benz's on the road, and NOT scrap them.



BTW: Yesterday I pumped more MMO in the cylinders and put the glow plugs back in. I tried to start it again, with the same results. The battery was fully charged, and the engine warm from the block heaters being on for several hours. The car was sitting in the sun as well.

Putting around town for awhile, then a valve adjustment, then an unusual 3k of highway miles? I would adjust the valves again before doing anything.

That sounds like a good plan. The cover has to come off to pull the head anyway, so I will check the clearance on all the valves before proceeding. Who knows, I may get lucky.....Rich

He said if it has an engine issue he’s going to sell it for parts as in the whole car. So what’s the point in wasting the time? I know exactly what a leakdown test does and tells. No point behind in it a parts car

Not a bad idea but I wouldn’t go further on it. Sell it for parts. If someone’s super curious of what the issue is let the next guy do a leakdown. Or blow compressed air in the cylinder like Diseasel said. Easy to pop out four glow plugs.

Does anyone else see the conflict in these two statements?

Proper Diagnosis & Repair
 

"
Because a leakdown will tell you specifically what is wrong with the engine.

A mechanic won't get very far with some customers if you only tell them " the engine is junk " '

THIS I've been a journeyman mechanic for a long time and I remember peole sells me nice used cars for $50 ~ $250 because their 'mechanic' told them exactly this, no details, so I'd do the usual due diligence is diagnosis then deferred maintenance and have a good running car I could then wash & wax, sell at a serious profit .(occasionally one was *so* good I'd keep it a few years)

" A bit of a blanket statement there Chief don't you think? "

Yes, obviously so because it's a fact : if you don't understand it, you'll denigrate a thing .

As Rich says, he like me, doesn't like to break up otherwise good vehicles if there's an affordable repaid in the offing .

A valve job is a simple thing, if there's more wear / damage to the engine there's an art form to overhauling versus rebuilding, I've been doing it for fifty years and often had people who bought a used car from me tell me "! ha ! I go one over on you man, this car has a rebuilt engine and you didn't even know else you'd have asked for more !" .

Not the case at all ~ I just do a better job than the average lazy person and it shows in the finished product .

Either you know, of you don't, simple .

More like the similarity of those who's first response is always "no" :rolleyes: .

:rolleyes: so glad you were able to point that out. there’s zero point... but I was suggesting if rich is so curious he can blow compressed air in the cylinders since he said was interested versus using a leakdown tester and breaking out unnecessary equipment.. But it’s still a waste of time.

Gee, the only piece of equipment that is needed to get % readings in a leakdown test is a gauge set between the engine adapter and air hose. I'd hardly call that " breaking out the equipment. " This car does not need a gauge set to perform a leak down.

There are two kinds of mechanics. One knows how to change parts ( wrench turner ) and the other that understands why they are changing parts ( engineer ).

I'll also note that the dealership mechanic deals with vastly different problems than the independent. Dealerships work more with failed parts on a very narrow range of newer cars where as an independent works on a wide range of cars and deals more with worn / out of calibration items. The independent must have a good grasp of how a car works in order to decide what needs replaced.