Loud "pop"...car billowed thick black smoke from...engine fluctuates then stalls

Loud "pop"...car billowed thick black smoke from...engine fluctuates then stalls

I have a few questions that I would be most thankful for any help.

SYMPTOMS
On my way home from the VW dealer today, my B5.5 TDI made a loud "pop", which sounded similar to the sound that a "potato gun" makes when launching a potato. Immediately thereafter, I noticed thick black smoke billowing from the exhaust. Then, the engine started to surge and lose power. I immediately pulled off to the side of the road. Called VW dealer and had car flat bedded back to dealer. There was no CEL light visible, but I am sure there are some codes that were thrown.

BACKGROUND
My car had some front end damage, which I took to the dealer to have repaired. The repairs consisted of straightening the front frame rails (as they were slightly bent) as I noticed that prior to repairs, that the front hood was sticking slightly over the front grill, similar to a person who has an over-bite. Some of the pieces that were replaced were: front support bracket (that runs horizontally), the cross tube, buffers, etc.

DIAGNOSIS?
I am guessing that in order to repair the front end of the car, that the intercooler and related plumbing had to be removed. So, I am guessing that the intercooler was not put on properly and blew off?

OTHER
The car currently has 123,000 miles and has been very reliable. The car was "unchained" at around 90,000 miles.

I appreciate any help that you all can provide. I am at a loss as to the problem. However, I want to be as informed as possible so that I don't get screwed by the dealer.

Thanks very much,
Andrew

More than likely an intercooler hose blew off. Wouldn't be the first time. It is sometimes hard to see just by looking at them whether they are seated properly. And sometimes the clips get bent and don't hold properly.

Thanks very much for the reply.

That is my guess as well. Probably the clamps have become weakened as they have been removed a couple of times (I had to go back to dealer twice, and each time they had to remove the the front bumper and all related pieces to get at the cross members and frame rails.)

I will post back tomorrow at some point with the diagnosis so to help other members who may encounter a similar situation.

Sounds like the dealer might have left one of the charge air hose retaining clips in the open or service position when putting it back together, or maybe left one out entirely. There's really no need to pull the bumper cover to access all of the charge air hoses. I recently replaced the turbo-to-crossover tube hose and all of the o-ring seals in the rest of the connectors. Just drop the skid plate to get to the turbo hose on the passenger side from the bottom; the intercooler hoses on the driver's side can be R & R'd from the top.

Check the "U" shaped clips as m-v ^ suggests, and the ears on the hose connectors for wear.

Sounds like a sloppy collision repair, The intercooler itself was probably damaged but not replaced, and would make that type of sound when it comes unglued, rather than ust a hose popping off.

Thanks so much for all of the replies.

The collision repair was indeed sloopy. I had to go back twice to get the car body repaired correctly.

The VW dealer called and stated that the retaining clamps were left off of the hose, which caused it to pop off. When I go back to pick up the car, I am going to double check that the dealer performed a leak check on the system.

Are there any other areas related to the intercooler that I should go back at the dealer for? I want to be reasonable, but at the same time I want the VW dealer to be accountable for any other potential damages.

Again, thank you for all of the replies, and once I get the final invoice and talk to the service manager to get the full details, then I will report back.

Romping down on it a few times will be the be the best leak test you can try.

To err is human, to really screw something up requires a dealer.