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

sfsegui · #1 09-26-2022, 06:41 PM

Took the plunge and bought a 2007 GL320 CDI for my wife. Purchased in Florida and trailered home last week. Extensive service records and was used by the wife of the owner of a European import repair shop. All biggies look to have been taken care of, recently at that (oil cooler seals, new turbo, airmatic suspension, etc.).

Has 200,000 miles, 2 owners, never left state of FL, clean title, in fantastic condition all the way around.

Wife told me yesterday that coolant message came on. I topped off with Zerex G05. Today, she ran to grocery store and when she returned, I smelled coolant, coolant message returned, and noticeable heavy leak from underneath.

Raised hood and inspected, no leaks I could see. Drove front of car on ramps and removed underbody shields. Saw coolant in several places-still couldn’t determine where coming from. Only thing I could determine was leak or was not coming from radiator or coolant reservoir.

Started car while on ramps, after a few seconds, a squeal started - sounded like it was coming from near the coolant reservoir (this was not a belt squeal, sounded like an electrical squeal if that makes sense). Tried unsuccessfully to attach pic of where noise was coming from. It sounded like it was coming from underneath the box where all the brake lines converge beside the coolant reservoir.

Leak became much heavier after car warmed back up to operating temp.

I am going to take it to an Indy when I return home (going out of town for work tomorrow, returning Wed) to diagnose only.

I plan on doing most/all work on this-besides things that need a lift.

I am used to the 602/603/606 engines, but looking at the 642 was intimidating to say the least. Sure I will get used to it.

Checked records and nothing about radiator or water pump being replaced in last 50,000 miles.

If water pump was on way out would these leaks be common (heavier at operating temp, leaks toward rear of engine, etc.

Thanks any insight.

jay_bob · #2 10-03-2022, 06:35 AM

Check the back left corner, the EGR valve has coolant lines going to it, that cool the EGR valve, as well as the EGR heat exchanger that is located under the intake manifolds.

Several small rubber hoses back there that could have sprung a small leak.

Once you get the leak sorted I recommend a water pump and thermostat change just for trouble prevention purposes.

jay_bob · #3 10-03-2022, 03:24 PM

You are aware of the brake booster recall right?

sfsegui · #4 10-03-2022, 06:52 PM

Yes, as soon as I get diagnosis back from ******** in W. Columbia I plan to in to have recall addressed. Appreciate the response/help jay_bob. Will let you know as soon as mechanic gets back to me.

Again, really appreciate the advice!!

sfsegui · #5 10-03-2022, 06:53 PM

Blocked out Germans Autowerks in W. Columbia for some reason.

jay_bob · #6 10-04-2022, 04:08 PM

Here is the thread about the brake booster issue I started

Urgent recall for W164, X164, R251 - brake booster

sfsegui · #7 10-07-2022, 05:41 PM

Just heard back from shop regarding coolant leak. Said coolant leak was coming from deep in the engine valley, said will be very labor intensive that includes resealing the intake manifold. Quote was $3000.

I am picking the car up Monday and will get a more definitive answer on exactly where the leak is coming from, what parts are required to remedy, etc.

This is my first foray into the OM642, all my previous engine work has been on the 606, 603, and 602.

Removing the intake manifold, they said it needs to be “resealed,” when I used to see any sealant on the 60x engines I automatically thought some hack has really screwed something up. Is sealant used on the 642 intake manifolds? Or did the person telling me what was wrong with the vehicle misspeak? In the past when removing/installing intake manifolds, I have only ever replaced the gaskets, never used sealant of any kind.

I have always had good experiences with this shop and I trust their diagnosis (they have always been on the pricey side, but I knew that going in).

Going to search for coolant system routing on the 642 and Monday I plan on ordering the parts (also going to include water pump, thermostat as preventative maintenance on JayBobs suggestion). If anyone knows where I can find a cooling schematic or if any other suggestions on ways to help or parts to preemptively change, please let me know.

My wife is somewhat unhappy as I transferred the tag on her old ML (getting ready to sell) and put on the GL so she is out of transportation until I can fix the GL, so I may have to take a few days off work when parts arrive to complete job as soon as possible.

Will keep posting on this, hopefully not to long, ordeal.

87tdwagen · #8 10-07-2022, 06:43 PM

If your coolant is coming from deep inside the V of the engine, your possible culprits are EGR cooler, oil cooler, or possibly intake seals. All of which can be addressed at the same time, there is little difference in labor between either repair as 95% of the work is the same.

You can get oil cooler seal kits from several vendors that contain all of the gaskets needed to do them all.

All seals are gaskets, rubber seals, O-rings, or metal seals. I have not encountered any RTV anywhere.

If you can work on the OM60x engines, you can handle the OM642. The biggest sore point is the tight packaging. You often have to remove a host of items just to get to what you want to. Like the aforementioned oil cooler seals. It sits in the middle if the V. To get to it you must remove the air intake, turbo, turbo pedestal, intake manifolds etc.

Very doable, but time intensive. There are lots of detailed tutorial on the forum on the how to, and youtube vids should you decide to tackle it. I did mine 2 weeks ago, took 5 solid days, but mine was for an oil leak, so a lot if that time was cleaning. Figure on 3-4 days first time doing it.

sfsegui · #9 10-07-2022, 07:47 PM

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.

I appreciate your words about if I can work on the 60x engines I can work on these. That makes me feel better.

I am jumping in feet first with this engine, as opposed to the 60x engines where I started slow by changing the oil, then I got a little braver and did motor mounts, then did a front main seal, and so on and so forth.

At least now (as opposed to when I got my 87 300TD about 13 years ago), I actually have a garage to work in (much better than driveway), a decent set of tools, and the means to acquire the OE parts/speciality tools, etc. The trade off is I also have young children, wife, good job that take up most of my free time.

Thanks again for the input and anything else you think of please feel free to let me know.

-Scott

Murkybenz · #10 10-08-2022, 04:54 AM

Possible leak source and most likely considering oil cooler seals were recently done is the join tube between the two halves of the inlet manifolds. It’s at the front and has two o rings , one for each inlet manifold.

87tdwagen · #11 10-08-2022, 12:25 PM

Quote:

Originally Posted by Murkybenz

Possible leak source and most likely considering oil cooler seals were recently done is the join tube between the two halves of the inlet manifolds. It’s at the front and has two o rings , one for each inlet manifold.

Murkybenz raises an excellent potential leak source. Lukily this one is relatively easy to check, the intake coolant union pipe referenced, sits just below and to the right of the thermostat housing. Should be easy to see with a good light while the engine is running at temp.

New Tools needed, not bad, but if you plan on wrenching on the om642 you will need an assortment of Torx bits and External (E) Torx sockets. Both short and deep well. You can buy a complete set or individually as you go, the vast majority of bolts are either E10 or E12. Those two will cover 90%or better of your wrenching needs. Wobble sockets and an assortment of extensionsill get you covered.

jay_bob · #12 10-08-2022, 10:00 PM

I have been there and done that, you will also need that injector socket to undo the hard lines without breaking things. Let me know if you need any help, I am up in NE Columbia (Lake Carolina) and can lend it to you.

sfsegui · #13 10-09-2022, 09:54 AM

Thanks for the suggestions and thank you for the offer of help jaybob, I just may take you up on that (I live in Forest Acres-just off Atescadero Dr).

I believe I already have the tools needed. Injector socket (same as the 606 correct?), e-torx sockets (purchased a set when working on 02 ML), all ready to go.

The injector harness tool-the Baum tool- looks to be unavailable or at the least will have to ship from Germany so I may want to borrow that from you jaybob if that is possible (would gladly give you a deposit).

I am going to have to purchase another torque wrench. I have a Hazet 40-200 NM, but looking at the torque values for these bolts/fasteners, I am going to order/pick up a suitable one for the lower values. Probably just a Craftsman 3/8 or if anyone has a suggestion on a quality one that is not to expensive, I am all ears.

My plan is to get the car back tomorrow, go through all parts that need to be ordered and order, set up my garage (table for parts removed, baggies, cart for tools needed set up, etc.).

Unfortunately, I am going to have to re-register and tag my wife’s ML. I originally transferred the tag to the GL and dropped the insurance on the ML. While this is not ideal, I don’t won’t wife to be without transportation as I travel a good bit for work. This isn’t all bad because I forgot to get windshield replaced before I cancelled.

Going to subscribe to alldatadiy.com later this afternoon and print out the applicable pages and place in binder. I have a CD I purchased off ebay a few years ago that I believe includes the X164, but have know idea where it is.

Anxious, nervous, excited, etc to jump in and get this issue resolved.

Thanks again for all comments, suggestions, etc. I am going to try and record this repair (I have a Go-Pro type camera that is attached to a headband) and hopefully will be able to post when finished or post a video/screenshot when questions come up.

-Scott

WaarrEagle · #14 10-10-2022, 12:09 PM

I bought a bootleg version of Mercedes WIS (service manual) on e-bay for $10. If you search Mercedes WIS you can find several option available for download. It has been a lifesaver for my OM642 and I have not done anything as big as what are you about to do.

t walgamuth · #15 10-10-2022, 10:36 PM

you sure its not coming out the exhaust? 2''which would indicate head gasket or cracked head.