Replacing Oil cooler seals or intake manifolds


DIY'er: 2007 Sprinter, 136k miles
I wrote this to be a comprehensive take on replacing oil cooler seals (or the oil cooler or manifolds). I regret not having found something on here like this, and ultimately, as helpful and amazing as the forum is, I think one way it could improve is in having a specific page on the forum where one could easily navigate to definitive write-ups on maintenance and repairs: rather than having 10 separate posts with people replacing oil cooler seals, we aggregate and consolidate it into one definitive post. As I sometimes feel like a prodigal son on these forums—getting what I need and then returning six months later when something else is wrong—I’m happy to write a post like this where I can offer something in a concrete way that will hopefully provide value to others. In a way, this is a debt that can’t be settled: experts who receive essentially nothing and provide their continual expertise. But this is one small way I can return the favor, offsetting the need to answer the same questions again and again.

I will take into account responses to this post and will update my posting accordingly, as there are people with far more experience than myself on this forum. Feel free to correcting terminology. Also, I need to go through and add some of the toque specs…if anyone has these easily accessible, feel free to post these below, and I will update accordingly.

Obviously, everyone is at different levels. I’ve tried to incorporate footnotes to prevent the real meat of the write-up from becoming an overgrowth of twigs and tangents. The primary audience here is the somewhat experienced DIY’er.

A. First things first (answering a common question):
Is this job for me?
If you have young kids or a wife (that you enjoy spending time with), let someone else do the job. If you are either strapped for cash, or enjoy doing this kind of stuff, then read on.

If you don’t have much experience, it’s not the best job to get your hands dirty with (they will get very dirty), but it will give you a good overview of the engine. Whether or not you succeed, I think has more bearing on your mindset, then on your capabilities (evinced by footnote 1: two anecdotes from Dennis of experienced mechanics with insufficient capacity for the job). Organization is probably the most important skill here. Retroactively, I’ve added meticulousness. If you have the capacity to be both organized and meticulous, then continue reading.

If you don’t have a garage, driveway, or parking lot where you won’t be bothered (for days to weeks), find the closest Sprinter mechanic that charges a reasonable rate and open your pockets. (Likely, your manifolds will need to be cleaned, and other stuff may arise, stripped bolts/threads, and there’s no certainty when you’ll be done.) As a first time job by a DIY’er, you can’t rush this repair. You just can’t.

This leads into the final point I’ll make on the “is this job for me?” segment. The cost-benefit analysis. The benefit is that You save anywhere from $1500 - 4500 on repairs and you learn some important stuff that will assist in future repairs. The possible cost (of failure) is another engine. There’s a healthy dose of fear here: and it’s probably worth reading this thread: I will be pointing back to it through this write-up

How long will it take?
If you ask Katjek1, he will tell you that his neighbor, working on a sedan 642, took 12 hours, adding that it was his first time. This will be to the ire of Dennis who will be quick to clarify that a sedan is different than a sprinter. If you ask Stone Sprinter Guy, he will tell you that he cut out a 6*6 piece of firewall from the passenger side and took a total of 30 hours. 98Firebird writes ( “As a DIY first time around I would expect it to take you 2-3 weekends working some very late hours.” If you ask me, I will tell you that I worked on it a little bit each (or every other) day for the course of a few weeks. No golf club was ever thrown and sanity remained (mostly) intact, though it was definitely waning toward the end. Dennis writes: “This job can be fairly easy, or develop into a total sideways job with very poor outcomes, that in some cases can wreck an engine.” So in short, it depends who you ask, and it depends what you encounter. If it were only as easy as the MB manual makes it out to be in footnote 2, the answer would not be…a very long time.

I offer one analogy to further afford you procrastination in beginning this job: Five or six years ago, when I was traveling west, I stopped in the Grand Canyon for a descent and several night stay in the valley. The trails were festooned with warnings not to hike it in one day. Is it possible? Sure—it’s been done…by very fit people, with the right equipment. Inevitably, there are those who misjudge their fitness and capacities. The same could be said for this job. But I think slow and steady is a good proverb to follow here. Once you’ve removed everything, you’ve made your descent into the Canyon. Now it’s time to climb back out. Bon voyage!

B. Let’s begin.
So you’ve decided to proceed with the repair:


These are the most important things you will read. They supersede everything else. Without following these, you dramatically increase the likelihood of your engine seizing and turning into the “sideways” job that Dennis speaks of.

-Tape off the manifolds once you have them off. Stick lint-free paper towels (I use the blue ones) in any other open holes. Tape-off turbo charger to pedestal.
-The area around the cooler must be absolutely clean to avoid contamination dropping down into the oil galleries as this will potentially wreck an engine. See footnote 3 where Dennis comments on a filthy valley. You can also re-read (or read) this thread again:
-Drain your coolant.
-Have a torque wrench for reinstallation.
-I also think that an E-Torx set should be added here. Everything just works so much better. I now own one…I did not when I did this repair, and that was stupid. You can get a set for $30 ( To be honest, I did not really know what an E-Torx set was; I thought sockets were sockets. They are not; E-torx will fit like a glove (and prevent the job from going side-ways). You really only need an 8, 10, and a couple others (which I can fill in retroactively).
-Remove jewelry, watches, rings, etc.

Parts you’ll need:
-Gasket set
-Oil cooler (See footnote 4)
-Anything else you break.

To remove, or not remove, the engine… is that the question?
No, it’s not. If you have the tools and wherewithall to remove the engine, do it. I can only imagine how infinitely easier (less likely to strip bolt heads, etc.) the job would have been with 360 access to the engine. I don’t have the lift for that, I don’t know how to do it, so (naturally) I did everything with the engine mis en place. This opinion (of engine removal and pulling the “power pack” forward is supported by Dennis, turbo911, firebat45, Bazookabob ( Apparently the power pack is the engine and tranny. I didn’t know what that was either.

What else should I replace/check, while I’m doing this job?
If you do take on the job, I’d say replace the fuel filter, glow plugs, and belts and water pump, as well as radiator (if it needs it). When I replaced the water pump, it took me forever…here, it was practically right in front of me, and would’ve taken an extra thirty or so minutes.
-anti-seize on glowplugs, clean off with brake-clean.
-also possibly thermostat (if needed).
-if others add to responses, I will update here accodingly

Key ideas
I think there are some key ideas that are helpful to consider.

I. The purpose is to get to the oil cooler (or, if you’re replacing your intake manifolds, those). You can’t get to the oil cooler without removing the intake manifolds. For the intake manifolds to come out, both the turbo and the EGR must be moved. So everything is in service of those objectives: removing the turbo and the EGR. You actually don’t have to fully remove the turbo or the EGR to complete the job, but I noticed that you might as well remove the turbo (as it must nearly be out anyway). On the other hand, if I were to do this again, I think the best approach would be to pull the EGR from the right/left manifolds, but not to remove it completely. I think a lot of time could be saved with this approach. Others feel free to correct me if this approach would not work.

I removed things (unscrewed screws) I didn’t have to, and hopefully this write-up will save you that frustration.

II. Another key idea is to focus on one component at a time, such that you can remove the screws and label them/bag. 98Firebird talks about this, perhaps I’ll add a bit more here later.

III. This kind of goes hand in hand with the previous idea, but you’ll be unscrewing many bolts. My best piece of advice is to be organized. I unscrewed bolts, I took a picture, and I put the bolts down on a large box in that order. I wasn’t perfect about that, and I would’ve saved time if I was. The job isn’t frustrating in the way that removing a fan clutch without a tool or replacing the water pump and taking forever to align it with the gasket and bolts can be. Many bolts didn’t give me much of an issue; mostly they’re hidden. It’s a lot of head scratching. I did it over the period of a several weeks, plugging away a bit every other day. I think that saved me a bit of frustration. I’m sure there were times where thirty minutes elapsed before a single bolt was unscrewed.

My method of taking a picture and adding the bolt to a long line of screws was flawed in that I had to pickup my space each night. Else this might’ve worked. But overall, I received several helpful methods (Katjek1, etc) use cardboard and paper and put the screws into those (with a drawn template of the part). I like this idea, and it could save a lot of time, especially if you’re doing the repair over many weeks. I also think that Manwith/withoutagun’s idea of using ziplock baggies for the different component parts would be sufficient for reassembly. As stated above, my retrospective opinion is that it is best to compartmentalize the job, a la 98Firebird (resist the urge to just go at any bolt you see), and if you do that, take the ziplock baggie, write the part name with a black sharpie and attach it to the part (if that part is removed). 98Firebird writes: As far as all the screws it's just like working on anything else for the first time, remove the component and either thread the screws back in the holes or drop them into the holes they go onto on the component removed and you'll be just fine.” Any of those will work, just choose one and stick with it.

Other Resources:
There was one Youtube that was head above shoulders the best thing I found. It’s a time-lapse, it’s informative, and it’s to the point:
. He stops the video to go over important points. On the other hand, if Zimaleta is your thing, then it’s a youtube search away. Knock yourself out. My penchant is not for unedited, peripatetic footage of Youtubers placing equal weight on their (mis-approximated) personalities as the actual purpose of the video. I don’t see why different “seasons” are necessary for mechanic videos. Note that the youtube video is of a sedan, which is the same engine, but different. (see above section: “How much time will this take?” where Katjek references the timing of his neighbor working on this vehicle and Dennis laments his continual reference to “a bloody E class passenger car as a benchmark”:

I stripped bolts. Now what?
Ordering from McMaster seems like the best bet.

C. Let’s really begin:
First steps:
Just follow this to get all preliminary stuff: airbox, hoses, engine covers.

Get the wiring harness/hoses out of the way.
Pretty much every connector needs to be undone, but be a little methodical.

1) Think about what would be in the way of removing the manifolds
2) Take pictures of all the connectors you undo.
3) It often seems that no connector is the same, but if there’s one certainty in life it must be that using a screw driver and force on these things will lead to breaking. Just try to figure out where the latching happens. (If others want to add more about this, I can update accordingly).

Remove Fuel Filter
-Clip is on there pretty hard and o-ring makes this difficult to pull off.
-Remove the two fuel lines taking pictures of which goes where.
-You’ll need to reuse the bracket and electrical connector screwed into the bracket on the fuel filter.

Remove fuel rails from above manifolds:
-Large brass bolts (most are 18mm, some are smaller).
-I only removed these from the fuel rails, such that the fuel lines are still bolted at the injectors.
-When reassembling, make sure these bolts are on there tight…there are stories of leaking diesel from the fuel lines, leading to non-starting.

EGR cooler
-The time-lapse video attached earlier goes over this.
-Again, I’d recommend not completely removing. Just undo the three bolts by the intake manifold. Loosen the bolts at the bottom of the EGR (and a bracket on the left side), and the one long bolt in the middle.
(Retorque to what?: )
-I may update this if enough people are of the belief that it is preferable to completely remove the EGR.

Remove Turbo:
Removing the turbo is probably the hardest part of the job.

There are four bolts mounting the turbo. The closest two are easy to find and use a t-torx, the back two are bolted and are incredibly hard to locate. Even having located them with my hand, and then grabbing a socket, I’d have to thumb around for them again. One thing I never found anyone point out was that if you crouch and squint below the driver side manifold, just above the oil cooler, you can see one of the hard to spot bolts mounting the turbo and can adjust your socket (from above) accordingly.

There will be three bolts attaching both right and left exhaust.

Two other bolts attaching the EGR tube. Again, watch the time-lapse Youtube. It goes over that.

Now, do whatever you have to do get the Turbo out. I find twisting it the bottom of the Turbo up and toward the passenger side works best. (Will update accordingly with other people’s suggestions).

However, to remove the turbo I did not remove the exhaust completely. You’ll find the two smaller diameter exhaust pipes, push those down and back, such that you can push the main exhaust even further back then you otherwise could’ve. You have to push this up and toward the back, and it might be helpful to stick a can of PB blaster in between the manifolds and the exhaust outlet to give more room. To be clear, I don’t know that my way is the best way. I’d easily be convinced that it isn’t. I did start unbolting the EGR cooler at one point (got five bolts in and decided that there were a couple that were just difficult to get to and returned to my previous approach).

You need to be careful here of the oil feed going through pedestal and into the turbo. Cover these holes!

Removing manifolds
(Prior to removing the manifolds, I would remove glow plugs and stuff those holes with blue lint-free paper towel).
-Rather than removing the swirl actuator motor from both manifolds, only remove from from one side. You can use two screwdrivers to insert into the tabs. Be careful here, these tabs can be fragile.
-Manifold: There are 9 bolts on both right and left manifolds. Should come out pretty easy. One of them is pretty far back in the rear.
-Torqued at 20.34 N.m (180 lbs. in.)

Remove Turbo pedestal:
-Four 10mm bolts that are incredibly tight (2 front, 2 back)
-PB Blaster and let it marinate. Have dinner, play with the kids. Spray it again.
-Fair warning: I stripped 3 of the heads on mine (not horribly). I ended up using a blow torch and a 3/8ths socket and consider myself lucky. I don’t think I would’ve had this issue were I using E-torx bits, which I now have.
-Toque specs?

There it is. Removing the Oil Cooler:
Don’t rush this. Go back and read the musts. I used the fine detailing attachments to a rigid vac and then sprayed with carb cleaner and wiped clean. Had I an air compressor I would’ve used that prior to spraying with carb cleaner (some use brake cleaner).
-there must be no dirt or debris in the valley before continuing.
-some have recommended an oil change after the job, just to be sure. I did change my oil after, but if you take all of these precautions, I think you’ll be fine.
-there are 10 oil cooler bolts.
-torque to 10.8 N·m (96 in. lbs.)
-make sure that you have the purple seals and a new oil cooler and remove the old cooler and seals and replace.

Now just do everything in reverse, remembering your gaskets.

(Again, will update with other’s suggestions/advice). Just provide in the comments.

If you feel this write-up saved you time, money, and/or frustration, please consider donating to the forum. ( This write-up could not have been made without it.


Last edited:


DIY'er: 2007 Sprinter, 136k miles
Here are the footnotes:

Footnote 1)
Dennis anecdotes (
“1) I hired a top ex US Navy trained diesel mechanic with all the right qualifications, but put him on this job and his careless approach wrecked an engine.
Poor fellow lacked focus, but seriously Lord Help US and the USN if they have such people working on effin warships.
I suppose it's a call for the late Erics, one a bruiser ex WW2 Bosun of the Royal Navy WW2 days, or the other POW ex Kriegsmarine mechanic who kept his engines running in the North Atlantic for 90 days. That will get you bloody well get you focused!!

2) The other a top tech from John Deere, with ASC's up the arse .
Poor guy couldn't/wouldn't use a torque wrench on this job for some reason, & undeclared , never used the new bolts & gaskets for the the job preferring to reuse worn take offs.
Result:- Gas leakages, & burning a whole engine harness and EKAS linkage,.
So in short after reading this, if you don't have the mental and physical dexterity nor focus or tooling on doing a job of this type, then get someone else to tackle it.

Footnote 2)
View attachment 228314

Footnote 3
Dennis writes that this is filthy, just as a point of reference:

Footnote 4:
The jury is a bit out on this one: some say the actual oil cooler can outlast the engine. But Dennis writes that “its impossible to remove solvents inside the cooler and upon start up oil will flow and wash the solvents & carbon into the main bearings wrecking #4 & #5 journals and seizing the shell bearings to the crank.” Plarkin writes that it “is not the place to save $.” I got a new one for ~$96 from Europarts SD. It’s cheap insurance for an enormous job and a pivotal part that leads directly into the engine.

Footnote 5:
If I have limited mechanical experience, what are some other things I should consider?

I’d choose leverage over force (longer wrench or ratchet); though many times, it’s a confined space and that isn’t an option. Definitely want some PB Blaster prior to embarking on this. I used Tough Stuff for cleaning off the engine. Use Berry Chemtool for cleaning out the manifolds and I used a harbor freight plastic scraper for removing the carbon deposits. Could also ship off to Clay in Grand Rapids, though I have a hunch that he’s placing in an ultrasonic cleaner, which you could buy as well.

Given that I was saving $2000+ on the job, I also bought some Wera Joker wrenches and sockets midway through (on sale). At one point, I felt like I was beginning to strip a bolt on the turbo, it just wasn’t worth it. It would’ve added several hours onto the job). I sprayed some penetrating oil a few times, and waited. Long universal spline wrenches can also be good to have. Mountain brand seem to be very reasonably priced: If you’re going to embark on this job, good tools are crucial. Buy once, cry once. Else you’ll be crying a lot. You don’t need a 365 piece mechanic set of many sockets you may never use, just a nice set of 3/8ths, a 1/4 ratchet with an adapter, some extensions. I also found a nice Cornwell 3/8ths torque wrench on Craigslist for reassembly. There are still a couple bolts I stripped, but fortunately, there were other bolts I could access to get the job done. (Again, get a small E-torx set).
-use a razor blade to clean off the manifolds, wipe down with carb-clean or brake-clean.
-my own personal opinion: start unscrewing any bolt with a ratchet where you have a better feel for the bolt’s release, then if you want to use an impact driver, do that. Maybe some of the mechanics here feel differently (and will update with their thoughts), but I think the chances of doing damage increases as the power increases.

Watch some Youtubes on best practices for mechanics (like the one below). Try tightening a screw that won’t loosen. Heat sometimes helps. Take a break…it’s not worth stripping a screw.

Last edited:

Top Bottom