Advice while its out. - PeachParts Mercedes-Benz Forum

Krautmister · #1 03-29-2006, 07:28 PM

I am doing 617 turbo into 240d 4spd. The 617 starts and runs awsome!!!, but is covered in oil. Since the engine is on the ground I'm having trouble convincing myself to do anything other than the gaskets. The chain shows zero stretch but the tensioning rail has considerable wear. The rear of the head gasket seems wet and has some oil trail from the seam. Guys this engine PURRRS!!!!, so I'm really worried about messing it up. I'm not afraid to tackle the head job, but if the head is off then I might as well pull the pistons and hone the cyl....... You see where I'm going? I don't want to do a 90% rebuild, but I would like to take advantage of the engine being out. I have thought about just sealing it up with all new gaskets and finishing the conversion. PLEASE HELP I have a chance to get really ahead on this engine!!!!, or really screw things up???? WHAT SHOULD I DO?????

krs · #2 03-29-2006, 07:44 PM

Man up and fix it.

Stevo · #3 03-29-2006, 08:35 PM

First clean the engine, that'l boost your spirits then decide what to replace, the oil filter housing gasket, the short little hose between T-stat housing and water pump, oil cooler hoses

. I would do that filter gasket at least.
Your heads proly fine. You'l really be jazzed when you get it all cleaned up but I wouldnt go doing anything to drastic as it sounds like she ready to run.

kip Foss · #4 03-29-2006, 08:37 PM

Be careful of the MAW syndrom. That stands for 'might as well', and it can cost you big bucks. You can MAW yourself from a valve job to new rings to bearings to an oil pump, to etc., etc. I did this on a 6.3 Chevy Diesel and went from a simple valve job to a $1,500 rebuild that I didn't really need.

Brian Carlton · #5 03-29-2006, 10:34 PM

Depending on the miles, now would be the time to do valves and valve guides...........and possibly prechambers.

I did this on the SD.......to the tune of about $900.........and I'm very satisfied with the results. The SD had 180K on the clock and it was definitely in need of new exhaust valves and guides and seals.

Naturally, if money is a factor, you can run it as original for 300K, but the improved starting performance is significant.

If the engine was maintained to any degree, I'd advise against going into the lower end.........very costly and not at all necessary.

Krautmister · #6 03-30-2006, 01:27 PM

Now that's some advice right there. Considering the mileage, cluster dead at 365k and the numbers match the car. Since the engine is original, I think the best thing to do is yank the head, do full chain guides, chain, gaskets, front and rear main seal, etc, etc.... I hate to but its better now than to put the car together and the old chain wad up after the first crank... Yes money does matter, several of you have been in this position before I'm sure so...... I'm still clueless even as writing this reply.....OH WELL THNX

signalredcoupe · #7 03-30-2006, 01:53 PM

I agree. Kinda what happened to me. Didn't want to get too much into it with such a sweet running engine. My head gasket was indeed leaking oil out the back. Pulled the head, sent it out, & found numerous cracks at the valve seats & other places. Yes, they will run perfect with minor cracks. Yes, the heads are prone to cracking. While the head is off - CHECK - the bearings & cylinder for wear. If proper oil changes were done, the wear will be minimal (if you're changing the rear seal, you have to pull the crank anyway). As Larry Bible says, it's not the chain, it's the guides. Change all the plastic that can self destruct the chain. Don't forget about the oil pump chain guide & tensioning spring-if your engine has them.
Also-the main timing chain tensioner & spring. At least your engine is out. Others on this forum - you guys have patience & guts - attempt these things with engine in car - in the North - in the cold. Hope all works out, Paul.

sailor15015 · #8 03-30-2006, 03:27 PM

I'm in the same boat you are, except my chain is about seven degrees stretched so I'll probably replace it too. My first Mercedes was hit in the end and totaled but I found a good body with a seized engine and now I'm about to have the engine out. Its also leaking at the front and rear of the head gasket. I'll probably pull it and do the valves and such. I have records from about 1995 and there's no mention of anything like that. The odo was dead when I got it at 160k and I know I've put at least 20k on it since that. It misses slightly on startup so hopefully the extra work will make it better. Its an '85 and after driving my '84, I realized that its also lacking a noticable amount of power.

Pete Burton · #9 03-30-2006, 04:36 PM

Quote:

Originally Posted by Krautmister

Now that's some advice right there. Considering the mileage, cluster dead at 365k and the numbers match the car. Since the engine is original, I think the best thing to do is yank the head, do full chain guides, chain, gaskets, front and rear main seal, etc, etc.... I hate to but its better now than to put the car together and the old chain wad up after the first crank... Yes money does matter, several of you have been in this position before I'm sure so...... I'm still clueless even as writing this reply.....OH WELL THNX

I have to agree with this too. make sure you get the right type of sealant between upper oil pan and block - you'll probably only do this once. Also, make note of compression before you take off the head. I think you can get the head right for a lot less than $500. I know Brian is real happy with the shop that did his, but he sort of likes to throw money at his car.......

Pete Burton · #10 03-30-2006, 04:57 PM

20 minutes and no reply.....he must have logged off. Maybe just let this one go?

Krautmister · #11 03-30-2006, 05:54 PM

Well, I must agree with all responses, money would be an issue if the head was removed. If the machine shop found cracks then I think it would total the engine for me. A replacement head of any resonable condition would be needing the same things probably as the old head. You guys are great, I am going for replacing the plastics and gasket the thing up...Thanks for the replys, and I will update as conversion progress moves on.

Brian Carlton · #12 03-30-2006, 06:43 PM

Quote:

Originally Posted by Pete Burton

I have to agree with this too. make sure you get the right type of sealant between upper oil pan and block - you'll probably only do this once. Also, make note of compression before you take off the head. I think you can get the head right for a lot less than $500. I know Brian is real happy with the shop that did his, but he sort of likes to throw money at his car.......

........definitely.

Seriously, if you do the head, odds are that you need exhaust valves. Metric will do that for about $400. The guides and seals add $150. if you buy OE.

The greater expense was the prechambers.........they could have been reused, but were on borrowed time.

Krautmister · #13 03-31-2006, 08:23 AM

The engine is out of W126, 83 300sd. I thought those did not have a seperate chain for oil pump?

Pete Burton · #14 03-31-2006, 08:58 AM

They do have a separate chain. I think the chain is pretty durable, but you should change the spring and tensioner on it. Chances are it will be pretty worn. Mine (at only 248K) had the chain through the tensioner face and the spring arm worn more than halfway through

Plus, I think you're looking at less than $10 for both.

signalredcoupe · #15 03-31-2006, 09:34 AM

I just had the dealer order the parts for the oil pump timing chain. My guide was well worn. What really scared me was the fact that the spring had a broken end to it by the guide. I hope it went down & out with the next oil change. The spring had also worn a gouge in the bushing it sits around. All parts were well within reason except the spring had to come from Germany & was like $18. Paul.