KNOCK after oil change on initial startup ! OH MY! possible engine damage? - Page 2 - PeachParts Mercedes-Benz Forum

cudaspaz · #16 03-03-2006, 04:46 PM

Disconnect the single wire green lead on the EZL.(ignition Module).

86560SEL · #17 03-03-2006, 10:00 PM

Thats right Paul - it is a 380SE. I do believe it is the same "layout" as the 4.2L. Attached is a photo of my engine

I was unsure about disconnecting the coil wire, but seems like it is OK as you mentioned your mechanics suggested it.

I am not sure how that canister was full of oil before. I was assuming that after I saw it was nearly empty last evening that perhaps it had an anti-drainback valve and the cheap one I bought did not. Since you mentioned that you poured oil into the canister and it drained out, that it would have made no difference on mine - unless I had some sort of special filter before.

Quote:

Originally Posted by Benzadmiral

86560SEL,

You say that the car is a 3.8-liter V-8 (so yours would be a 380SE or -SEL?). I had the big brother to it, a 420SEL. Now while I've never peeked under the hood of the 380, I'm guessing the layout would be the same. Two points:

1) My long-time independent MB mechanic in Denver taught me to disconnect the coil wire before I cranked the engine too. Sometimes it took 10-15 seconds to get that oil pressure up, but it was worth it for the peace of mind, knowing that the oil was flowing where it needed to go. My W202 C230 doesn't have a distributor anyway, and as Duke2.6 pointed out, it may not be a good thing to do with modern electronic ignitions. But the W126 was fine.

2) How was it that the oil filter canister could be full of oil? When I'd undo the cap and lift out the filter (and I used real MB filters from the dealer or from Fastlane), there would be very little oil in the bottom of the canister. I tried pouring oil in there to prime things, and it would just drain right into the engine. Maybe something -- dirt from the old filter -- temporarily blocked the draining of the oil from the canister?

Nipperiley · #18 03-03-2006, 11:19 PM

I recently sold a 1986 560 SEL. I purchased the car with 69K miles and sold it with 200K miles. I changed the oil every 3K miles with MBZ oil filters. There was never much oil in the metal canister. Just a few teaspoons at the bottom. The filter came with the copper washer for the drain plug, the alum washer for the canister bolt and a rubber o-ring washer for the canister top seal. It did sometimes make some valve noice very briefly upon startup, but nothing too loud.

86560SEL · #19 03-03-2006, 11:38 PM

Thanks - so obviously, even these MB filters (canister type which mine is) does not have an anti-drainback valve. I have no idea why my canister was full when I changed the oil back in December - perhaps a faulty filter? I am just hoping that 1 second "ZZRRR" sound on startup goes away with the MB filter installed again. I will know Sunday morning when I drive the car again and will report.

At any rate, I did not use any of those washers provided with the filter. I know I reused the one on the drain plug and I am assuming the one that goes on the canister lid was also still there. As mentioned- I thought those were for a different engine.

Nipperiley · #20 03-04-2006, 12:38 AM

The copper drain plug washer is the most important NOT to reuse. I hate oil leaks. You can sand down the old washer and perhaps reuse it, but just get a new one (which will come with some MBZ filters).

86560SEL · #21 03-05-2006, 10:57 PM

Yeah - I just reused the same washer on the dain bolt and no leaks.

The "ZZRRR" sound was not as loud this morning when I started it. Now that the oil has been in there today and driven, we will see if it does it on Tuesday AM, which is when I will drive it again.

Still has that knocking sound though, ONLY between 1500-1800 RPMS, (on acceleration) which has me extremely concerned. I guess I am paranoid now since it had that loud knock when I first started it after the oil change. It has always had this slight knocking (between 1500-1800 RPMS on accelerations), but it seemed to be louder a couple of times today, but that was when I had the radio off. When the radio is on, I cannot hear it at all. Strange, but a couple of times today, I was trying to hear it at those RPMS, and I could not hear it at all. Seems to come and go now. I am hoping it is not a rod or something, but knowing my luck lately with cars, it probably is. I had never read anything about anyone else with a V8 Mercedes having a knock, but I suppose I am the first. For what I paid for it- I will just continue to drive it until it throws a rod out of the side of the engine, if that is indeed what it is. I had a mechanic and my father listen to it and they seem to think it is just the lifters making the noise.

Perhaps I can put some sort of additive in the engine to further provide

Nipperiley · #22 03-06-2006, 02:43 PM

I forget that there was a problem with some of the camshafts on the 1986 560 SEL's. Mine was one of them. There were made from too soft an alloy or something. It DID start making a loud valve knock. The lobs had worn down (around 100K miles). Both needed to be replaced with newer model.
A good MBZ mechanic would know which of the 86's had the bad camshafts. I don't know about the dealer, I don't think there was ever a recall

86560SEL · #23 03-06-2006, 06:58 PM

Thanks - the car I have now/referring to is actually a 1985 380SE, with 264,890 miles. My user name was from before. I do know that the cam on the passenger side (lobes I can see) look worn down and I have lifter noise on that side. Could it be the worn cams causing that knock? Will it ruin the engine if I do not replace them?

Quote:

Originally Posted by Nipperiley

I forget that there was a problem with some of the camshafts on the 1986 560SEL's. Mine was one of them. There were made from too soft an alloy or something. It DID start making a loud valve knock. The lobs had worn down (around 100K miles). Both needed to be replaced with newer model.
A good MBZ mechanic would know which of the 86's had the bad camshafts. I don't know about the dealer, I don't think there was ever a recall

Matt L · #24 03-06-2006, 11:11 PM

Quote:

Originally Posted by Nipperiley

The copper drain plug washer is the most important NOT to reuse. I hate oil leaks. You can sand down the old washer and perhaps reuse it, but just get a new one (which will come with some MBZ filters).

You're being paranoid. I've reused copper crush washers dozens of times with no leaks, and that's sealing gasoline on a Bosch K-Jetronic system in a Saab, running at 40 PSI rather than less than one, as in your oil drain plug. If they do leak, sandpaper is not the answer, as you can leave the sides other than parallel. The trick is to anneal the washer if it leaks and you don't have a replacement.

Nipperiley · #25 03-07-2006, 12:35 AM

This seems to have become a two part question:

1. Re the camshaft: I am not an expert on camshafts, but I do think that they have a hard metal "skin" on the out of the lobes and softer metal under that; so once you have worn thru that outer layer it will not take long to really wear the lobe down. The valves will not open all the way after that.

As we all know Chev and Ford aftermarket cams are GREAT for only a hundred plus US buckos, but all MBZ parts are 5 times that. I used MBZ cams for my 86 560, but there were others parts available, but still expensive.

2. Re the copper washer. I realize that the oil pan washer is no big deal since there is not that much presure there and oil is viscious. But with a fuel filter I would be anal, with gasoline I would use a new crush washer and if not available I would massage the old washer to make it perfect. No one wants leaking fuel.

86560SEL · #26 03-07-2006, 12:55 AM

Yes, it has turned into what seems to be a 3 part question.

Well, that is marvelous news about the camshaft.

Now I know I should not spend a lot of $$$ on this car. I will drive it easily, until it stops I suppose, then buy a new car. The power is still pretty good now, so hopefully I have a few more thousand miles to go.

Does this problem happen to the diesels? Seems they can go 500K+ miles without this problem, but the gasoline engines cannot, or can they and I just happen to have a poorly maintained car?

Quote:

Originally Posted by Nipperiley

Re the camshaft: I am not an expert on camshafts, but I do think that they have a hard metal "skin" on the out of the lobes and softer metal under that; so once you have worn thru that outer layer it will not take long to really wear the lobe down. The valves will not open all the way after that.