To oil pump or not to oil pump? - PeachParts Mercedes-Benz Forum

New2MB · #1 07-25-2007, 01:59 PM

I'm getting ready to reassemble my engine ('87 SDL) and put it back in the car and one thing keeps bugging me... the oil pump. Seeing as how I would have to pull the engine again to work on it I hate to leave it undone, however the damn thing is $250!

I have no indication that the oil pump needs changing, the screen is clean, no sludge anywhere. The pump sprocket and chain appear to be in good condition and I replaced the chain guide which was only slightly worn.

The engine has about 167k on it. Searching through the forums it doesn't seem like many people experience issues with the oil pump. So the $250 question is, should I replace the oil pump?

rrgrassi · #2 07-25-2007, 02:01 PM

$250 is cheap insurance. Just like on the OM617, it's cheap insurance to replace the oil pump and it's drive chain.

New2MB · #3 07-25-2007, 03:09 PM

Add it up to all the other "insurance" items I've bought and I'd have to say that insurance is not cheap, but being able to rely on my car IS priceless.

I'm somewhere in between the "if it ain't broke don't fix it" camp and the "fix everything before it breaks" camp.

When an oil pump goes bad, is it usually a certain part of it that fails?

Is there any way for me to measure the wear that the pump has incurred?

TheDon · #4 07-25-2007, 03:15 PM

250$ is cheap.. the oil pump for the 617 is 514$ on fastlane

vstech · #5 07-25-2007, 04:03 PM

everything else being rebuilt, put in new pump chain and pump... you will be sorry if you don't.

rrgrassi · #6 07-25-2007, 04:15 PM

IIRC, older gasser American cars had used a feeler guage to check for wear on the oil pumps. Most were drivin off of the cam gear or the distrubutor shaft. The Ford POS 1.9 l in the old Escort was a gear type like in some auto trannies, and also used a feeler guage.

New2MB · #7 07-25-2007, 09:07 PM

Alright, an oil pump it is.

Anything in particular to watch out for when replacing it?

#8 07-25-2007, 10:56 PM

Quote:

Originally Posted by TheDon

250$ is cheap.. the oil pump for the 617 is 514$ on fastlane

I just replaced the oil pump and chain on my 617 (almost 400K miles), and I'm lucky I caught it when I did (check out the photo of the chain):

617 Oil Pump Chain

t walgamuth · #9 07-26-2007, 07:07 AM

If it were me, I would take it to my favorite machinist and he would look at it and say whether it needs rebuilding or replacing. I think in most cases we put in new gears if rebuilding because of wear. If rebuilding because of another type of failure, it might be fine to use as is.

The examination by an experienced machinist is the proof of the pudding.

When rebuilding a benz I never throw new parts at them without determining whether the old ones meet wear guidelines or not. The parts are too expensive and the factory parts are so well made, why replace if not needed?

Tom W

New2MB · #10 07-26-2007, 09:31 AM

My machinist died a few years ago and I don't know enough to judge for myself. I just hope the new part is made as good as the OEM was (with my luck the OEM would last another 250k while the replacement will only last 100k).

To help me pay for my $250 oil pump the local police decided to pull me over this morning, I had no idea why until he told me that I was doing 73 in a 55. My cruise was set at 61 and I had taken the route to avoid the noisy chaotic highway, go figure. Thanks Van Buren Department of Government Revenue Generation, you have upheld your integrity once again by proving to me that police are lying thieves.

vstech · #11 07-26-2007, 11:07 AM

any time I get pulled and the cop tells me I was going faster than I KNOW I was, I insist they show it to me on the radar gun. if they can't, they have to let you go...
I have gotten out of two tickets this way now.
a lot of the cops have their gun set to "trip" at a set speed, and it doesn't show them how fast you are actually going, they use their "judgement" to hit you with a speed, basically, they pull the number out of their A##... call them on it, you will get away.

New2MB · #12 07-26-2007, 11:13 AM

Thanks, I'll remember that at court and next time this happens. I'm always guilty so I wasn't prepared for that situation.

New2MB · #13 07-26-2007, 03:43 PM

One last question regarding the oil pump.

If/when the oil pump goes out what would most likely happen?

Valves seize up, pistons hit valves, cam cracks, towers crack, timing chain snaps, etc...

WINGAS · #14 07-26-2007, 08:54 PM

NAw, just eats up all the internal bearings and munches your cam, which sends metal THROUGHOUT the engine. I donnow, how much is a NEW crank for these?

For one, I never "freshen" an engine w/o an oil pump, but until recently they were inexpensive $24 for a big block. Now, the $24 are crap, and you ahve to spend near $100.

Nonetheless, regardless of the itnernal engine components ( and rebuilding a MBZ is the same cost as a RACE Chevy, it also a matter of my time R&R the thing. I hate doing things twice.

Ask me about the rear seal I decided not to mess with , even though the engine was out and upside down on a stand.