Head gasket failure, without overheating?

[d.b]

Scenerio:

BMW Service has my car. I had it towed there after speaking with a S63tu guru about what could be causing my car to become hard to start and him telling me it sounded like fuel injectors and that the warranty on them had been extended ___NOT RECALLED___ (presumably to save BMW money...). My car is MY2014 with 67k miles.

Coincedentally, somewhere from the time that I last drove it, to the time that the tow truck picked it up and took it to BMW service, all of the coolant drained out through one of the turbo lines. The last time that I drove the car, there were no low coolant warnings, no smell, no overheating, no white smoke, no steam, no visible coolant leak to be seen. The last time that I saw the car, the engine compartment was open and I was trying to start it with a couple of mechanics at a tire shop to no avail. Coolant leaking everywhere would have been impossible to miss, and I have already confirmed that there is no possible way that I could have made the 11 mile drive on a hot day in atlanta with no coolant running through the engine.

Note - the car did run on the warm side, with a message about 20-30 seconds (cold start) saying that the engine temp was high. This is a message that I had been getting for a week or so and started around the time that the car started becoming hard to start. (Push button, turn over and over and stop, push button again and it would start - and then a 3rd push, etc). I was monitoring the temps closely at all times during this period both on the dash and via dashcommand/obd kiwi3 and they were never at alarming levels.

Every bit of what I just said was relayed nearly word for word to the service center, along with suggestions to check the fuel injectors.

The first time that I hear back about the car, 'It needs a new engine, it looks like the car ingested water'. $32k.

I responded - did you check the injectors? they are under warranty extension because they are known to cause problems and instead of recalling them, you guys elected to fix after they have caused a problem.

They checked the injectors and sure enough, all signs point to the engine flooding with fuel - plugs are fouled, scoring in cylinder walls... 'OK, we can probably get the engine covered as consequential damage'.

a couple of weeks pass. I follow up to see status and give approval to have the coolant line replaced. The injectors and plugs are replaced under warranty.

The tech has changed his mind at this point about the scoring in the cylinder walls and now believes that it is just carbon build up, and tells me that one of the other techs in the shop doesn't think the engine needs to be replaced. He said that they worked on it a bit and were able to prime the engine and it started right up after doing so and putting a battery charger on it.

The coolant line is replaced, battery replaced, everything is reconnected and the car is filled with coolant.

My next conversation with him:

'So, after the cooling system was pressurized and we got the car started, coolant breached the head gasket. This is caused by overheating'.

My question to you all:

Is it possible for the head gasket to have failed because of the engine being flooded with fuel from the injector and possible hydrolocking at some point?

What I do know, is that the last time the car was driven it did not have a blown head gasket, or at least not bad enough to cause any of the coolant to leak out during the drive. I'm the only person who drives the car, and I have never seen temps even close to high enough to blow it.

What also odd, is that i got an email that my car is ready for pick up - injectors/plugs covered by warranty and the bill goes to me for coolant line, and there is no mention anywhere of an issue with the engine or head gasket.

oh, I've never seen a single message or light in the car for a low coolant warning. The only explanation that could possibly exist for an overheating scenario is if the guys at the tire shop did it while I wasnt there - which I highly, highly doubt to the point that it really isn't a consideration.

Any ideas?

[Craze]

your car was hard to start and had high temp warning for a week?

That was the first sign it should have gone to dealer

[d.b]

Originally Posted by Craze

your car was hard to start and had high temp warning for a week?

That was the first sign it should have gone to dealer

agreed, but I had to park it as I was 2 months into unemployment and hadn't started a new job at that point. I was hoping to figure out what the issue was and fix it myself.

[Craze]

I feel for you
But also these cars arent ls motors
Anything suspicious should be treated with caution

When mine had a missfire i was panicking lol

Problem with bmw is whatever they say goes unless u have a really strong case

[d.b]

I'm just hoping that someone will come along who will know definitively one way or another if a connection can be made between the two, I don't care how unlikely it is only that its possible... if it is, my case is very good.

[technician117]

Your hard start would be connected to the injectors. If the engine hydrolocked it would have bent a rod. These internals are really not that great in that regard. Also excess fuel/hydrolocking would not cause a blown gasket. A lean condition AKA clogged injector could potentially blow a head gasket but it's more likely to burn the piston first. These injectors are known to leak anyway, not clog.

The connection is the problems in your coolant system to the head gasket (if it is actually even bad). Running low on coolant may not show any overheating condition on the temp gauge but could easily allow air pocket hot spots in the heads. Those hot spots could cause a head gasket to burn up. There's your connection unfortunately. Do you remember which coolant reservoir needed to be topped off? The one on the side of the engine bay with no measurement is the important one. Really dumb for BMW to put the less important one front and center in the bay. I do believe the other one has a low coolant level sensor. I'll have to check the document to confirm.

EDIT - I did check and confirm that the firewall located coolant filler is the tank with a coolant level sensor.

[d.b]

Originally Posted by technician117

Your hard start would be connected to the injectors. If the engine hydrolocked it would have bent a rod. These internals are really not that great in that regard. Also excess fuel/hydrolocking would not cause a blown gasket. A lean condition AKA clogged injector could potentially blow a head gasket but it's more likely to burn the piston first. These injectors are known to leak anyway, not clog.

The connection is the problems in your coolant system to the head gasket (if it is actually even bad). Running low on coolant may not show any overheating condition on the temp gauge but could easily allow air pocket hot spots in the heads. Those hot spots could cause a head gasket to burn up. There's your connection unfortunately. Do you remember which coolant reservoir needed to be topped off? The one on the side of the engine bay with no measurement is the important one. Really dumb for BMW to put the less important one front and center in the bay. I do believe the other one has a low coolant level sensor. I'll have to check the document to confirm.

EDIT - I did check and confirm that the firewall located coolant filler is the tank with a coolant level sensor.

The car was never driven with low coolant. I checked it regularly and the pipe that was broken must have been broken after that last drive. I was under the hood trying to start the car after having the tires installed and it was not leaking or broken at that point. The first I heard of the broken hose was a few days later after it had been towed.

I just realized that I failed to mention that the original destination was an independent German car shop and they are the ones who told me that the hose was broken and it arrived with no coolant in the engine circuit (but the turbo circuit was full - I realize the error in that statement from your last post in the other thread, but this is what their s63tu 'expert' told me via text). Upon learning of the injector warranty I opted to have it towed to BMW, which is where this thread picks up.

[d.b]

Also of note - the bmw tech originally thought that the cylinder walls were scored, but later decided it was more likely carbon buildup.

Thanks again

[wallyman424]

That statement is pretty bizarre. There should be no carbon buildup on the cylinder walls. They're either scored or they're not. Carbon builds up on the Piston face and valves, not the walls where the Piston travels

[Sophisticated Redneck]

Originally Posted by d.b

Also of note - the bmw tech originally thought that the cylinder walls were scored, but later decided it was more likely carbon buildup.

Thanks again

As another poster mentioned, that is a bizarre statement and makes me question the skill of the tech....Carbon just doesn't build up on the cylinder walls except for there first 5mm or so where the rings don't touch. See the pic of my 150,000 mile N63 below that I took down to do the valve stem seals and de-carbonize it, notice the walls are nice and clean save for the first 5mm or so. Yours should look the same, if not better.

All of your questions can be answered with a good borescope. I have to tell you it is not very confidence inspiring that the shop you took it too didn't use one.

I Highly recommend this unit: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It has two cameras, one at 90 degree which is perfect for checking out your cylinder walls. It records video and photos. Before you drop 30k, invest 270 dollars in a decent borescope and check it out for yourself to be sure.

And as for your original question, I will second what another poster said. You don't blow a head gasket from water, you bend rods that way. Get the borsecope and look for yourself or give to mechanic and tell them to show you pics of each cylinder before you decide to replace. something they should have done in first place.