New TDI owner with a couple issues

Just got my first TDI but I grew up with NA VW diesels and have had diesel trucks. Car has 298K on it and I have no idea of maintenance history but it fires right up. Issues with the TDI are a complete lack of boost (top speed of 67 mph), grind/crunch when shifting into 1st at a stop (no noise when moving), and some alternative electrical engineering from the power block to the injection pump (I think). I've pulled the intake hose off the turbo and turned it by hand. It's smooth and easy to turn. I also tried moving the vane rod and it developed resistance after about a 1/2" of movement which is correct I think. I was going to try running the car without the turbo vac line hooked up and use my mighty vac on it to adjust the vanes but the car was completely dead. Pretty sure it's due to the electrical engineering. It's a switch that keeps the car from starting somehow. I'm planning to pull it out if I can but I don't know the wiring of the car. Not sure if the crunch is clutch, slave, fork, or what. I'm open to any and all ideas.

Try the low power link in my signature for ideas.
Disconnecting the turbo hose won't tell you much. Try running it without the MAF.
There's not much in the way of electric controls on these things, the wires are pretty small and sometimes get damaged.
The first check of the turbo would be to see if the lever moves all the way at start-up.
Check this thread, first post for links to a lot of good reading, it will help you become familiar with your TDI

Unhooked maf and it runs the same (maybe a little better). Pulled the random switch and wiring out also. Mighty vac on the turbo actuator with the motor running. Turbo starts to audibly spool up at 13". Can't hear it at all below that. It spools up when I put the egr vac line on the actuator. The motor won't rev above 2400rpm in neutral either and gives off some acrid white smoke. Going to check actuator for operation and holding vacuum along with N75 operation tomorrow.

Found a couple of things. Turbo actuator won't hold vacuum. It went from 18" to 0 in less than 10 seconds (has new vacuum lines). Also found the check valve that feeds to the vac reservoir and N75 doesn't check anymore. I've got a check valve from my motorcycles emissions stuff that works in place of the stock part and a new actuator on the way. Hopefully that fixes the issues. Only issues is I don't know which way the check valve is supposed to be oriented. Should it stop flow from the vacuum pump side or the vacuum reservoir side?

Might have found at least part of the problem. Intake has a little soot in it.

angrywasp said:

Might have found at least part of the problem. Intake has a little soot in it.

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I think that's ALH TDI course 101...lol.

Mine was plugged a little worse than that when I bought it, and it too wouldn't rev past about 2400 RPM.

That's just the beginning. You have to get that all cleaned out before doing anything else...and be very very careful not to get any of it in the engine. Besides the intake manifold being plugged up, the intake ports in the head will be well coked up as well. Be careful cleaning it.

Once you know the intake is nice and clean, check the operation of the MAF and turbo, verify timing is correct, and all filters are changed and fresh.

Rem

There's a chance that the intake ports on the head might NOT need cleaning. With my two TDIs (both purchased with the Clogged Intake option) one required cleaning and the other not: my car was like Rembrant's, it pretty much wimped out around 2,400 rpm; my wife's car ran the rpm range fairly readily, only a slight lull around 3,200 rpm; so, which car's intake head ports needed cleaning? my wife's!

That said, always try to prepare for the worst! Study up on cleaning those intake ports on the head.

UhOh said:

With my two TDIs (both purchased with the Clogged Intake option)

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Hahaha...ain't that the truth...lol.

Yes, mine came with the entire inconvenience package:
Clogged intake, bad MAF, sticky turbo, and 160k mile fuel filter...lol.

There are SO many issues with these cars that are SO common (and well documented), you can dig right into the repairs without even doing a ton of troubleshooting (in the beginning). Getting that intake and EGR all cleaned out is a must though...can't really do or check anything else until that's taken care of.

Rem

Just got done cleaning the intake and egr valve. Incredible how much crud fits in there. Ports had some soot in them but not nearly as bad as the intake. Just waiting on some new gaskets to arrive to bolt it back together.

Car runs much better now. Hits highway speeds pretty easily. It di go to limp mode though. Accelerating in 3rd with the turbo spooled up and suddenly no turbo whistle. Guess I'll readjust the new actuator when I get the car back from the tint shop and install the new style maf when it arrives.

Good work! Best "performance" improvement you can make! As ugly as it was I'm kind of glad I had to go through this operation (OK, once was enough, but had to do it TWICE! two cars...), as it has ingrained in me that they need to be run with a bit of gusto every now and then to help keep this buildup down.

Regarding your comment about transmission grind into first, are we thinking this is a clutch issue or perhaps just linkage adjustment (see YouTube video from Diesel Geek on adjustment procedure)? I can highly recommend the Diesel Geek Sigma 5 short shifter (have them in both my cars): along with AC Delco Synchromesh w/Friction Modifiers my car is a joy to shift; my wife's car is really good, but just not quite as nice as mine in this regard (more miles on hers; might also give another shot -third time a charm?- at adjusting the linkage).