CVCA Head Gasket

[MB2VW]

My partners kid managed to overheat his 2015 Passat, and is told by a shop they'll do the Head gasket for $3k...

News kinda sketchy at moment, and will find out more in morning ..

Thought I would throw it out here for anybody thoughts, experience or suggestions...

Thanks!

Will have.more to story in AM...

 

[MB2VW]

Checking a search of the forum this AM, it seems head gasket / overheat issues on TDI's are rare... Can't imagine how he managed to let this happen...

 

[MB2VW]

Well this came back to haunt me...

My partner's son took over this car, from our mini fleet of our business. Let's just say, the car was treated like an appliance.... Some how the car overheated, and the car was taken to a local mechanic somewhere outside my purview. My partner told me that the garage insisted the engine was toast, and was trying to sell him a expensive used motor replacement. There was a small coolant hose that blew out on the rear of the engine, and he authorized the garage to order the hose and replacement. Last week he picked the car up, and the car ran fine. The mechanic added some sort of additive to fix any small head gasket leak, and claimed one of the cylinders had low compression. The car was driven two hundred miles (ORL to MIA) and I met the car last Friday...

The car is due at now at 120k for timing belt/ water pump job, and I offered to do the job. The car started fine, and there was not evidence of cross contamination in coolant or oil. Yesterday I drove the car to my house in preparation of the pending timing belt job.

The drive home was, well interesting.. The car ran fine, I got on the expressway and got to 70 mph no problem. But 5 minutes into my expressway entrance, the damn temp gauge went from 190 deg (twelve o'clock) to just below the red zone. Holy smokes. I backed off the throttle and the temp started to fall. I called my partner, and asked him ***? did his son have any issues on the 200 mi journey, and he said he didn't know... As we were talking, the temp gauge immediately went straight down to 190 deg. No CEL, car ran fine. then it would climb up to do around 2 o'clock, and then go back to twelve oclock 190 deg. It did that once again for a moment, and then the rest of the 40 mile drive home were no more needle excursions.

Thoughts that come to mind, 1: Water pump solenoid, shroud? 2: Air in system? 3: Bad temp sender? 4: Thermostat?

Also how does one check compression on the CVCA? I need to dig into that one...

I'll keep you posted!

Thanks for any ideas or suggestions!

 

[oilhammer]

Most likely will need the engine replaced.

The heater core may be clogged up, and the vent line assembly is probably full of crud. That's what started it.

Pull the plugs out, pressure test the cooling system overnight. I'll bet you'll find coolant in one of the cylinders next morning.

Now if you want to tear that engine apart, be my guest. You are going to find very expensive pieces warped.

 

[740GLE]

did it eat any coolant in your +200 mile journey since the shop touched it?

 

[MB2VW]

Sorry for my delay, had a busy week...

I'm in wrench mode this morning... so after the trip to my house, the car was parked and I didn't look at it until today.

I noted the overflow tank was empty. Maybe it was working out air. I put a litre of 50/50 coolant in and ran it at idle to 190 ° .

I planned on doing the timing belt pump, but after oil hammer's advice, I'm going to be sure we are not doing something I will regret doing later...


Funny you mentioned the heater core, as I did my inspection, I suspected such a calamity... as i see the small hose the previous tech replaced was on the inlet to the driver side inlet to core... I'm gonna go out and crank up the heater now and see if we have any hot air... Will post back in a bit...

 

[MB2VW]

Pull the plugs out, pressure test the cooling system overnight. I'll bet you'll find coolant in one of the cylinders next morning.

Don't you mean injector? That begs the Q: Should I pull the injectors out? yikes..

 

[x1800MODMY360x]

Don't you mean injector? That begs the Q: Should I pull the injectors out? yikes..

I think he ment the glow plugs.

 

[MB2VW]

I think he ment the glow plugs.

I looked at removing injector/glow plug. Doesn't look so scary...

Gotta find a pressure tester, maybe the dreaded Harbor Freight has one I can try.

I did try the heater, and in the works of Mick Jagger, She is so cold cold cold...

As usual OilHammer is all knowing, all seeing....

 

[MB2VW]

decided on just pressurizing system overnight and see if pressure falls, due to potential injector complications, such as replacing stretch bolts and potential breakage. I figure if pressure drops, i can look for puddles or steam from exhaust pipe...

Have pressure tester via amazon on order, will try tomorrow when it arrives.

 

[MB2VW]

Update:

Nifty cooling system rig worked well sealing up coolant bottle.

Amazon Link Pressure tester

At 12:40pm I pumped in 15psi, and by 2:20pm we were down to 13 PSI.....

7pm@ 10.5psi. I removed it and started car. Nothing unusual at tail pipe or startup....

I hooked gauge on my 2015 SEL, and pumped it to 15psi to see a comparison...

 

[oilhammer]

If you are suspecting an internal consumption of coolant, you really should pull the plugs out.

You know what happens when you pressure test a cooling system, and there IS a leak, and it DOES push coolant into the cylinders, and you DON'T have the plugs out?

When you go to start the engine, the coolant doesn't magically jump back into the water jacket... it stays in the cylinder. Do you know what happens when you try and compress a liquid? If you are lucky, the starter just won't turn the engine (and you may burn the starter motor up). If you are not so lucky, or continue to try to start the engines, the rods may just decide to do this:

 

[MB2VW]

Ouch!

Sir, when you say pull plugs out, are you suggesting removing injectors? I reviewed a video on the ea288, and it mentioned the stretch bolts, which made me reluctant to pursue yesterday. The video showed a tiny orifice into the cylinder after injector was removed, and I wondered how I would peak in cylinder with just that. Any suggestion would as always be much appreciated.


Luckily I didn't have bad luck when I did fire it up.


I did a leakdown on the other cvca Passat and it too leaked down.

Just trying to determine if this car is worth rehab...

 

[oilhammer]

Plugs.... glow plugs.... (there are no spark plugs on a diesel).

 

[MB2VW]

I thought injector had an integrated glow plug...

 

[oilhammer]

No, it does not.

The glow plug has an integrated cylinder pressure sensor.

 

[MB2VW]

Ah ok... thanks for the clarification.

Will try leakdown again and take a peek as soon as I can get to it...

 

[MB2VW]

Work has kept me out from under the hood lately, but I did manage to accomplish a leak down test, and a borescope inspection of two cars in the driveway.

Lessons learned:
1: Thoroughly blow out glow plug hole with compressed air, before removal of plug. (Oppsie on my first plug). Even then there will still be a case of some crap falling in.

2: My newly acquired Milwaukee 3150-20 mechanic borescope doesn't time stamp. Marker photos are the best way to keep track of what shot is what.

I ran a series of shots before pumping up the cooling system to 15psi. I let it site 12 hours, ran a series of shots, then waited another 12 hours, keeping it pumped up to 15psi. The borescope has a side view lens, so you will see some valve and Cyl Hd - Gasket - Block shots.

I did run a series on the non overheated car, just to have a comparison.

I guess looking at these photos, the car is ok. But I humbly submit them here, and welcome any comments:

CRVA Cylinder Borescope Shots - Google Drive

drive.google.com

 

[MB2VW]

Wrap up:

I moved forward with the TB/Water Job, replaced the clogged heater core. After a thorough test drive, I was confident enough to do the rest of the differed repairs and maintenance. ( LF lower control arm rear bushing, DEF fluid injector missing gasket/exhaust leak, 40k service list, broke dpf sensor, alignment)

The car is running fine now, and my partner had the car detailed to make it less offensive to look at, and be seen in.

Car is being returned to driver tomorrow.

I did have moments of sadness, and wondered if this was the one that was going to kick my butt.... but it worked out.

Thanks for entertaining my story!

 

[pedroYUL]

Next time don't let others put any crapola leak sealant, specially in the cooling system.

Think about it, if the heater core was plugged with just the regular G12/13 in there, imagine the crud that can form with those sealants.

 

[MB2VW]

did it eat any coolant in your +200 mile journey since the shop touched it?

I wasn't the driver, and didn't see the launch of the trip. However on arrival, I recall some coolant in overflow. But after that weird trip I took, the bottle was dry the next morning.

FWIW...

 

[MB2VW]

Next time don't let others put any crapola leak sealant, specially in the cooling system.

Think about it, if the heater core was plugged with just the regular G12/13 in there, imagine the crud that can form with those sealants.

I'm not so sure that was the case here. But who knows what happened... I can tell you the core looked like hell.


Ugly Heater Core Pic