DevinT

Hello All,

Long story short I bought a 2014 E63S with ~52,000 miles back in September 2021 and it ended up having a preexisting blown head gasket for who knows how long. We found this out because the low coolant light came on and I kept having to top the car up with coolant. I only drove the vehicle a handful of times and was mainly just to and from a local shop as well as a Mercedes Benz dealership. I received $9,500 and also have $5,000 of third-party warranty I can use, so $14,500 of "free" money to use.

As of right now no one has taken the engine out and inspected it. Mercedes Benz recommends I buy a new or used engine and swap it out because the oil sample results (see attached) show a good amount of deterioration to the engine. This will cost me roughly $20,000 to buy a used engine with low/lowish miles and the labor to swap out the engine and I should be good as new or good as used (haha). My other option is having the engine inspected and possibly being able to just replace the head gaskets, resurface the heads, and maybe a few other things (bearings, etc etc.) I just would hate to spend $4,000 or so for someone to pull the engine and do an inspection just to be told it needs the engine replaced.

Some extra info... I put roughly 1,500 miles on the car myself (1,000 miles driving home and the rest was to and from Mercedes Benz over the course of a few months and also them driving it). The car has never overheated with me and appears to run just fine. Mercedes Benz did scope the cylinders before the oil sample and said they looked good. The car was with Mercedes Benz for a month and they could not figure out the issue so they sent in an oil sample and came to the conclusion of a blown head gasket. I also attached a photo of some random notes I took about the oil sample results as well as possible actions going forward. I am no mechanic or expert when it comes to engines so bear with me.

I just would like some input on what I should move forward with (engine swap or get it fixed). Feel free to ask any questions if I missed some important info.

BlownV8

I would get it fixed. If it is running and the cylinders are in good shape, have the heads resurfaced, new head gasket, and pocket the money. Don't drive it until you have it fixed since it could seize or bend/break a rod.

I.T. Guy

$20k seems really light for a used engine swap.
What if taking the heads off doesn't reveal anything wrong?

mbwillgrubs

So, your only indication that something is wrong is an oil sample?

PeterUbers

My question too.... why not just scope the cylinders? (At a different dealer) compression test? Why did you do the oil analysis?

CincyMBGuy

It sounds like the perfect time to bore, stroke, and big turbos.

GinDistiller

We need more info - what exactly is the complaint if it wasn't giving you any trouble driving, was coolant disappearing? Compression and leakdown test, if not done, should be #1 on the list and doesn't take very long, at least get a general sense of the internal health of the motor.

Also - $5k on a third party warranty...is that some kind of maximum limit of coverage? Usually the warranty costs you X$ and then should fully cover, minus any deductible and other things, whatever failures occur, so I'd be curious what your fine print is. I.e. if you pay to remove and inspect the engine if they will cover repairs going forward.

ygmn

find a good engine builder that knows the engine and let them recommend what to do.
This might be a speed shop but so be it.

IF it ran that long w/o dealer knowing head gasket was leaking must have been a very very minor leak - maybe just between cyinders and not water jacket.
If it runs now and no issue with a blown head gasket... should be reasonable easy fix of removing heads checking them out.
Cleaning lower block and maybe checking some bearings an put back together. heck you might have money left over for a tank of premium.

my guess is previous owner messed with engine and computer etc for more performance

sunil517

Scope the motor and if possible check a few rod bearing. The bottom of the motor should be sold since oil pressure was not an issue. I would just do head gaskets and turbo lines and hoses. My friend had this done on a 14 E550. problem is MB only replaced one head gasket and a new head under coverage.
Good time to change all those sensor that leak oil CPS lines and hoses.

I.T. Guy

I'm still interested in hearing what the problem is the Dealer cannot find besides the oil analysis.
"The car has never overheated with me and appears to run just fine."
Were there other issues in the first 1,000 km's beside the oil?

DevinT

Sorry for the late reply. Car loses coolant which was my only indicator that something was wrong. Assumed it was a coolant leak, but nothing indicated that even with all the tests we and/or the dealership did. Held pressure, no steam, no smell, no white smoke, combustion leak test kit showed nothing, the only sign was losing coolant which is evident it was getting into the oil.

DevinT

Sorry for the late reply. Held pressure, no steam, no smell, no white smoke, combustion leak test kit showed nothing, the only sign was losing coolant which is evident it was getting into the oil.
The warranty is called Route 66 Warranty. When I got the loan through my credit union they offered the warranty and it sounded incredible, but they never mentioned a $5,000 limit. No deductible just the upfront cost, but limited to $5,000. I only paid ~$1,800 for it so it ultimately will be worth it, but also not worth it at the same time. trust me I am going to go with a better warranty company and look into them more in depth.

DevinT

Thank you for your input! This is what I am hoping for. Next week I am taking it to a very reputable local mechanic who works on German vehicles (high end as well) to talk about the situation and have him pull the engine to check it out. If the engine is fixable I will have him replace the bearings whether it really needs it or not.

DevinT

Only issue I noticed was low coolant light came on and I would have to keep feeding her coolant. Next week I am more than likely getting the engine pulled and looked at. Hopefully just a minor blown head gasket to which they can resurface the heads, replace the head gaskets, and replace the bearings. I also read someone else mention on this thread "I would just do head gaskets and turbo lines and hoses" and "Good time to change all those sensor that leak oil CPS lines and hoses." so I will look into that as well.

DevinT

Update: I took the car to a local shop who specializes in German vehicles. They determined I should get a new engine. They ran a few tests and pulled some oil and let it sit. In the small jar they had the oil in was about 1/3 coolant and was very visible after letting it separate for a bit. They thought it would be better to just bite the bullet and throw a different engine in because the list of items that could be causing the coolant to mix with the oil is very long. It would basically be "exploratory surgery" they said. On top of that the possible wear and tear of anything or everything that the oil is supposed to lubricate. Just searching for a decent mileage M157.981 hopefully warrantied and known history on the donor car. Loose budget is around $15k. Thanks all.

BlownV8

If it were me, I would pull each spark plug. It should tell you if it is a head gasket issue or something else. You may be able to save quite a bit of money if you do the exploratory examination yourself. After pulling the plugs, buy a Harbor Freight scope and scope the cylinders to make sure the bores are good. The shop just wants to take the quick and expensive route and replace the engine. These engines do not have a slew of issues. With that said, if the engine was driven long in its current state, there could be wear issues. I would throw $3k for the chance to save $12k.

ygmn

1/3 coolant in oil?
Does dipstick show oil level over full?
If not where did this 1/3 oil go that was replaced by coolant?

Something weird is happening under that hood or mechanics not explaining everything corrrectly
Wonder if block is cracked somewhere?

Did someone not fill @ oil change or over time and add coolant as a prank or vandalism?
but you say you keep adding coolant to overflow.

Sell it!
Or look here for used engines - basic database of Junkyards:
Car-Part.com--Used Auto Parts Market

I see 4-5 engines on there 2014-2016
E63 (5.5L, VIN 7G, 6th and 7th digits)

DevinT

1/3 of the oil being coolant may have been an exaggeration. The small jar of oil did almost look like 1/3 coolant though after it separated. I do know that when I originally had the car at Mercedes Benz they mention the oil levels were high so they drained some oil. The cars burn some oil too so it may not get high levels as quickly maybe? You are correct that I kept having to add coolant as the low coolant light would come on or I would visibly see the coolant levels low. We are unsure of how long this has been going on since it at least has been happening since right when I got the vehicle. I am going to buy an engine and swap them out. I guess once the engine is out they can check it out. I have had Mercedes Benz and a local independent shop take a look and part of it is they just don't think it is worth me spending the money pulling, inspecting, and trying to fix. It will be a rabbit hole of issues going that route I guess.

DevinT

Hey, that was my original thought was to spend a small amount at the chance of saving a lot. I have had both Mercedes Benz and this local independent shop tell me I should replace the engine. Originally I told/wanted my local independent shop to pull the engine and inspect it, but before they did that they did some tests and looked into it then determined I shouldn't waste my money on the current engine. I got some money from the dealership I bought the car from so I am not taking much of a loss at all buying a different engine.

Rockster

Kind of a damned if you do damned if you don't.

A head gasket replacement could require a resurfacing of the head if there has been an erosion of the head from the leak. Even worse is the block deck may be degraded and a skim cut necessary to clean the block up. For this the engine has to be removed and disassembled. The head too of course.

You won't know the tech won't know until he has the head off and can check the head for straightness and the block mating surface for any damage from the leak. The tech if vary familiar with M-B engines might be able to offer some guidance that the head/block are probably (probably...) ok and just a new gasket is needed. But he can't know for sure until he has the head off.

Even if the head gasket is all that is needed then the oil is changed and the engine used for a while then another oil sample is obtained and analyzed. The hope is the wear metal levels drop to safe levels. They may. But they may not. That the bores look good though suggests (but no guarantee!) the wear meal levels would drop to a not a problem/concern level.

A used engine unless one has the ability to thoroughly check it out -- run it check compression even bore scope it and have the oil analyzed may be no better (and could even be worse) than the engine in the car.

A new engine is "better" as it will come with some warranty. But it ain't going to cheap to buy. But if the car is in good condition otherwise it might make sense (and cents...). The alternative is selling the car as it which means it probably won't bring you much money but whatever you get you put towards a replacement car.

Hard to know what's best. I could offer you consider having a good tech remove the head and after if he believes the block needs attention or finds some other reason to not proceed sell the car as is.

OTOH, if he believes the block is ok and the head is reusable or can be made reusable at a reasonable cost to do what is necessary to bring the head up to spec then replace the gasket.

Of course afterwards drain the oil and change the filter. Run engine some then drain the oil and replace the filter again.This to flush out any remaining coolant/water in the crankcase and to ensure any metal levels in the oil are way low so a subsequent oil analysis will not be impacted by the wear metals from before.

If the gasket stays leak free and the oil analysis has nothing scary just drive the car and keep your fingers crossed. If the engine manifests any signs of trouble arising from the leak then you can replace the engine or sell the car as is and move on.

Siegmann

Could simply be the oil cooler leaking fluids across a gasket.

DevinT

****UPDATE*****

I went ahead and purchased a used engine on eBay from a reputable seller. I will update again once they swap out the engines if I hear any more word about my "bad" engine.

PeterUbers

how much was the engine - and for the sake of others who may and will have similar issues - what determines a reputable dealer on eBay?

DevinT

Bought a used engine for $12,500. Donor car was a 2014 CLS63S with 72k miles that had a vandalized interior (was not in an accident) and comes with 90 day warranty. This was more miles than I was wanting, but too good to pass up. Reputable seller as in they have sold 7000+ items (tons of Mercedes Benz parts) with a 99.6% positive feedback score. I bought the engine from zavatskiyauto.

Bahnstormer

I've done several transactions with zavatskiyauto and the results were always good, never bought a whole engine though, lol. Anyway, best of luck with your rebuild Devin.