Possible Turbo Failure - My Beloved TDI

I think my turbo failed. Here's the summary of events:

1.) Loud POP and slow decompression noise while traveling 80MPH. Like air rushing out of a compression chamber through a small hole.

2.) Turbo whistles LOUD. Sounds like Toyota supra from fast and furious.

3.) Engine coolant light comes on. Coolant low. Been hiding coolant for last 9 months.

4.) Loss of power / low boost but I'm still truckin'.

5.) Lots of white smoke from exhaust, especially when I open the throttle or ascend a hill.


I was driving down the highway at 6AM the other day with throttle wide open on my 99.5 TDI, doing about 80MPH. It's very cold out and I'm running a bit late. The sun is shining and reflecting a bright pink hue off the snow covered mountains.

Then I hear a loud POP! And the subsequent sound of decompressing air. It wasn't a bang, or a boom, or a knock, but a distinct POP and a long slow decompression.

First thing I thought was I blew a hole in my exhaust or header. Then I thought a seal. I smell some anti-freeze. Its been leaking for the last 9 months and I wonder out loud where its been going. The anti-freeze light is now on.

I cleaned the turbo last year (oven cleaner method) when I did the intake manifold. I've had an over-boost issue for the last few years when I push it too hard under load. For example extended full throttle jaunts up a steep hill.

Immediately after the POP, my turbo sounds like a jet engine. Its whistling, and its whistling LOUD. It sounds kinda cool I thought. Yea, my car just turned into that supra from fast and the furious! Alright! The turbo sounds like its riding shot gun, beer in hand, laughing at me as I wonder if I'll make my important meeting. "You thought you'd make it to 350K you *******! hahahahaha."

F-U turbo.

Then the loss of power hits me as I try to ascend a hill. Low boost but good quick response from my new 60PSI Supra turbo. This baby spins up at 1300rpm and I'm so stupid I floor it to see what its got.

White smoke pours from the exhaust. Nobody tailgates me.

The car has about 319,000 miles on it. Did the timing belt around 305k.

I've been driving it around town just for ****s and giggles. And because I don't have another car. Then I remembered runaway diesel syndrome.

Anyone have a similar experience?

Sounds very much like you just popped a fitting/hose/pipe along your intake tract, post turbo. Get your car up on some ramps and check out your junctions from the turbo to the intercooler.

Find the boost leak and fix it. Having a turbo exposed to atmosphere isn't a great idea. I bet you have a failing head gasket. That's where the coolant is probably going. And it shouldn't take anywhere near WOT to sustain 80 MPH. If it does you've got other issues.

Time to show your beloved TDI some love.

If coolant is disappearing, and isn't a one time event and no external leak can be found, it's probably making its way to the cylinders (head gasket).

Thanks for the quick replies. After a bit of self-loathing I pulled her into a garage and took a peak.

The pancake pipe has a joint that just disconnected.

To answer your questions about the missing coolant, I believe its coming from the intercooler. I had an alignment done and they mentioned it on the invoice. Also, my driveway was complaining about something like that recently. I'll just keep fillin' her up. No time for non-sense. Last oil change was clean, no sign of head gasket issues.

Not sure I understand the white smoke though.

Oh, and no, I don't need to be WOT to sustain 80MPH. I just happened to be when the pipe disconnected. Thanks for you help, much appreciated.

White smoke could be your coolant burning up in the cylinders. Any sign of soot in your coolant bottle? Exhaust smell "funny"?

Your pancake pipe blew off for a reason: overboost. You should check your VNT actuator. Same thing happened to our Golf a few years ago and it turned out that the actuator was shot.

The intercooler is air/air and does not use coolant on an ALH.

Find the coolant problem. If it's a head gasket and you don't fix it you risk eroding the surfaces involved which will lunch the head or worse, the block.

Never mind that coolant that makes its way into the oil does severe damage to bearings.

Dealer could have said EGR cooler. Those sometimes leak. And boost pipes come off sometimes, doesn't always mean there's a boost issue.

IndigoBlueWagon said:

Dealer could have said EGR cooler. Those sometimes leak. And boost pipes come off sometimes, doesn't always mean there's a boost issue.

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Like IBW said.
Most likely scenario and least bad!
But don't let it slide; coolant loss can lead to overheating which causes more damage and coolant vapor in the intake is undesirable, too.

IndigoBlueWagon said:

..And boost pipes come off sometimes, doesn't always mean there's a boost issue.

Click to expand...

Maybe not "always", but it was the issue in my case. Just making a suggestion.

flee said:

Like IBW said.
Most likely scenario and least bad!
But don't let it slide; coolant loss can lead to overheating which causes more damage and coolant vapor in the intake is undesirable, too.

Click to expand...

Fairly easy to check; the biggest issue getting that out is partially draining the coolant and access (some of the air intake piping is in the way.)

Once you have it out put a MODEST amount of air pressure (~15psi) on the coolant side and stick it in a bucket of water. If it bubbles......