07 GL320 CDI Massive Coolant Leak - Page 3 - PeachParts Mercedes-Benz Forum

sfsegui · #31 11-16-2022, 06:10 PM

Had a few minutes today and began cleaning. Not to bad except when cleaning where the oil cooler sits, was having a little trouble getting what looked like sealant off. Was able to get it off and area cleaned up pretty good. Have the right side intake manifold sitting in a diesel bath currently. Haven’t cleaned an intake manifold since I did it on my 87 wagon years ago, still as disgusting as I remember. Below is a before and after

Now I really am convinced the coolant leak came from the oil cooler. I was starting to clean the oil cooler and I realized the previous owner/person who changed out the seals used sealant when installing the new seals. The below picture is of the sealant still left after wiping all of the filth off the bottom of oil cooler. Don’t believe a good seal could be made with that amount of sealant. Not sure with the OM642, but whenever I saw an engine (603, 602, 606) that had a bunch of sealant used on it, I always got worried about the quality of work done to it.

pawoSD · #32 11-16-2022, 08:17 PM

Reminds me of when I tore down my M116 to change out all the manifold seals/gaskets....looks like a similar experience.

Murkybenz · #33 11-17-2022, 06:46 AM

Possibly they refitted the old seals and added sealant ? , when I changed the ones on my Jeeps 642 engine to the purple ones the original orange ones were like new but if you refitted them to the cooler and ran a straightedge over them you could see there would hardly be any compression when torqued down for them to provide a seal.

My bad just realised seals you removed were purple ones so maybe the sealant stopped them from sealing properly ?

87tdwagen · #34 11-17-2022, 02:30 PM

My guess is if the viton purple seals were used, there are variations between aftermarket and OE. The OE seals will fit and hold in the cooler channels, the aftermarket ones are hit or miss. Possibly used RTV to hold them in place on the cooler for installation. Also used too much.

When I did mine, I did apply a layer of Hylomar to both sides of the seals. This provides the holding power to keep them in place when reinstalling and also allows the seal to adjust to mating surfaces when tightening, also it never fully hardens and appropriate for this type of use. If you don't have any, the seals should go in dry.

sfsegui · #35 11-20-2022, 05:33 PM

Oil cooler installed with new seals, then installed intake manifolds. Actually beginning to look like an engine again. Cleaning all the old sealant used by previous owner took the longest amount of time today. However, what almost took as long was cleaning the bolts to the oil cooler. After cleaning most of the bolts, I realized I had ordered new bolts so apparently I was just cleaning for practice. Torqued everything down to appropriate specs and replaced seals that were in the kit I ordered. The EPC and factory service manuals have been a lifesaver.

Have to work tomorrow but then off the rest of week so hopefully will be done around Thanksgiving day.

bhuvahh · #36 11-22-2022, 08:07 AM

I am researching as we speak. Even though the oil cooler seals were recently taken care of by previous owner, I am diving in to the thread about these that jaybob started to begin to wrap my ahead around this engine.

sfsegui · #37 11-22-2022, 08:54 AM

Only real advice I can give is to do what you are doing, dive into all the info you can. I was very intimidated by this engine when I decided to take on this project, however, it is really not as bad as I thought it was going to be. Actually, in many ways, I have come to believe it is easier to work on the OM642 than the 603 or 602.

While I am not finished putting everything back together, I hopefully am in the home stretch.

Just go slow, document everything you remove (order of removal, take pics, etc), and be prepared to not have something you need (had to order a new torque wrench-2 actually, new glow plug connectors, had to borrow a few tools, etc.).

Don’t try to do in a minimum amount of time either, this may lead to damaging something in a rush.

Obtain a copy of the WIS (factory service manual), I don’t see how this job is possible to do correctly without it. I was unable to print the pages I needed, but I just moved my old desktop computer to my workbench.

Good luck, this forum can walk you through any issues you may have.

sfsegui · #38 11-24-2022, 01:23 PM

Had a few hours last night after putting the kids to bed, so decided to at least get the swirl flap motor installed……..those clips are fragile, and I am talking about the new ones. Finally got it in, but didn’t seem right. Driver side flaps were open and passenger side flaps were closed and motor itself didn’t look like it was sitting correctly. Went back and looked at the pictures I took on removal and they were no help as I remember one of the old clips fell apart and the motor came right out. Last thing I want to do is getting everything put back together and have to go almost all the way back in because of this.

Called it a night and went inside and ended up going down the rabbit hole of YouTube videos regarding the swirl flap motor. Most of which were about the resistor trick. My intakes aren’t to gunked up, so really no need for this bypass, or so I thought. Did find a neat trick on how to install manifolds and swirl flap motor as one however.

Got up today and decided to remove manifolds and swirl flap motor to give me more room to get motor in correctly. Used “handle” trick from YouTube and pulled manifolds out. Got last swirlflap clip in. My problem again, is that the only way the motor goes back in is with the driver manifold flaps open and the passenger manifold flaps are closed. Pretty sure they both need to be OPEN or both CLOSED.

Is this correct? Doesn’t make sense if one is open and one is closed, and if I reinstall this way, surely would throw a code and go into limp mode.

I played with the arms and finally was able to get both sides of the flaps in the open position and went to bolt the swirl flap motor down. Then - POP - lower plastic tab of swirl motor broke, then while trying to carefully move swirl motor I heard the top tab crack and break. These are the tabs that bolt into the manifold to secure swirl flap motor. In picture below, you can see the lower broken, the top one I just put back in place but you can see where it is broken.

Below pic is of handle trick I did to remove manifolds.

Here are my options as I see them:

1. Secure intake flaps in the open position and do the resistor trick to fool computer. I know this may adversely effect fuel mileage a little and allow more exhaust to come out of the rear. I can live with that.

2. Buy a new swirl flap motor - don’t really want to drop a few more hundred dollars on a new motor because of damaging the housing. Aside from the money, I will have to wait several more days which keeps the car off the road. Going on 2 months since it has been driven.

3. Try and JB Weld the motor and secure it best as possible. This is most likely not going to be the route I choose as I am sure my repair will break in the very near future and I will be right back where I am now.

Any thoughts, insight, tips, brands of bourbon, etc are welcome and needed.

Happy Thanksgiving to everyone as well!!!

Murkybenz · #39 11-24-2022, 04:33 PM

Go the resistor route .I have no noticeable mileage loss or drivability on my jeeps om642.
I actually refitted all new clips to my swirl flap linkages when replacing turbo and cooler seals but chose to run the resistor anyway.

sfsegui · #40 12-06-2022, 04:40 PM

Intakes back in with swirl flap motor finally. All good there. Moved on to installing EGR actuator, also called Y27/9. Reattaching cooling lines and thought I had better put gasket on before I attach the final cooling line. Went through my kit, no gasket. My garage computer with WIS/EPC is so slow I have finished this post even before it has warmed up so I can check EPC.

Regardless, does anyone know if a gasket goes where I am pointing my finger in the second pic below, first pic is of me holding the actuator.

sfsegui · #41 12-06-2022, 08:09 PM

Computer finally warmed up and as far as I can tell there is no gasket according to the EPC. Looks like after 2010, the OM642 got a gasket in this spot on some models, Sprinters more specifically.

Goal is to get wiring harness and turbo reinstalled tomorrow.

pawoSD · #42 12-06-2022, 08:30 PM

Almost looks like a copper ring around the center of the EGR that seals down into the mating surface on the housing much like is used on some of the MB exhaust fittings.

Murkybenz · #43 12-07-2022, 02:37 AM

It’s just an o ring /rubber or possibly made of viton. My Jeep had the same.
Mercedes OM642 part number A0259973448

sfsegui · #44 12-13-2022, 06:27 PM

Everything put back together (finally), only took two months. Put fresh coolant, oil, etc. Primed fuel pump a few times, took a few tries but on the third try, roared to life.

Right off the bat, red coolant warning came on, said turn off vehicle! Inspected, no leaks. Left running for a few minutes, no leaks. Waited a few more minutes with vehicle off, no leaks-oil or coolant. Drove about 10 miles around town-scary with the red coolant warning , but returned home-no coolant leaks and reservoir is full (put 2 gallons 50/50 Zerex and distilled water).

Just checked the cardboard underneath, no leaks of any kind.

Checked codes, cleared, drove again and all 3 codes came back:

1. UO106 - lost communication with glow plug control module. Going to make sure all my connections are secure. The only thing I did regarding the glow plugs was replace a few of the broken plastic connectors. Chance I didn’t seat the metal connector far enough in the plastic housing on one of them.

2. P2010 - intake manifold runner control circuit high bank 1a. I did the 4.7 resistor mod. My only thought is I didn’t do it correctly? Will try another resistor or just plug the swirl flap motor back in. I did the 4.7 mod because 2 of the tabs on the swirl flap motor cracked. I repaired them, but not sure how long it will last where that motor is situated.

3. PO118 - Engine coolant temp sensor 1 circuit high. Only thing I can think of again is I didn’t reconnect sensor properly. DOES ANYONE KNOW WHERE THIS SENSOR IS LOCATED?? Hopefully I can get to it without having to remove to much.

None of these codes were present before I started tearing everything down. Funny thing is, the car drives so much better than it did before. Seems much faster.

I did hear the turbo whistle when I had the window down, doubt I am supposed to hear that, but not sure. Need to get a new bat wing soon as previous owner used rtv sealant to put the plastic together around the old orange gasket. Needless to say it was destroyed when I removed it. I used silicone tape and hopefully this repair will last until I get the new bat wing.

Will report back when and hopefully if I get these codes taken care of. At least it looks like I solved the coolant leak!!!

sfsegui · #45 12-13-2022, 07:44 PM

Right behind the crossover injection line. Pretty sure that will throw a code. Luckily this coolant sensor has been used on Mercedes from 2006-2021 on both gas and diesels. Hopefully my dealership will have it in stock.