Another P0243 wastegate code...
 

For the second time in as many weeks, my '98 E300 Turbodiesel has thrown the P0243 code at me while falling on its face in terms of power. Obviously I have no boost -- it's getting dumped somewhere. And boy does it make the car a total dog to drive! Freeway ramps have a whole new sort of excitement...

I figure it's either a vacuum line loose or with a hole in it, or a transducer that went kaput, from reading past threads. Does anyone have a photo of the transducer, or a diagram for it? Or a part number so I can order a spare through the dealer?

I'm (still) without power from Hurricane Ike -- six days and counting -- but I'm hoping to get this fixed over the weekend. She's no fun to drive right now at all. Thanks for any tips on what the parts look like or what I'm looking for when I get under there to examine.

Cheers, John

Follow the vacuum line from the wastegate (the vacuum actuated device on the bottom of the turbo) and you will find the transducer. It has three vacuum hoses and an electrical connector going to it. One hose is the source, one hose is the vent (goes to a little filter) and one goes to the wastegate.

On the other side of the car is another identical transducer. It is for the EGR valve. You can try swapping the transducers and see if the code comes back or moves to the EGR, or, what I would suggest you try first is replace the little filters on the ends of the vent hoses. I did this the last time I had the code and it has not come back. Do both the EGR and turbo wastegate vents. They cost only a few dollars each from the dealer. Try this and report back, but if that doesn't cure it then the transducer itself is the next suspect - but that costs $150-$200.

Good luck on your recovery from IKE, hopefully it won't be much longer before you get your power back.

I swapped the transducers at a campground a month ago. Took 15 minutes and no tools. No immed egr code, or return of the PO243 code, until yesterday.

Do the swap to confirm the transducer is OK. Then get the new vents Marty suggested.

Here is one lengthy thread on the subject:

http://www.peachparts.com/shopforum/diesel-discussion/145993-cel-p0243-malfunction-wastegate-solenoid-help-please.html?highlight=wastegate+solenoid+photo

Post #10 shows that the OP's problem was resolved by replacing the filters. In Post #17 Terry shows the PN for the filters which is 0000780956 and they currently cost about $6 each.

Thanks for the troubleshooting tips, gentlemen. Still no power at my house, but it looks like this is something I can work on easily enough. I'll call the dealership about the filters today -- I need to pick up a new belt and oil filter element as well. Will post back if I get the opportunity to poke around under the car.

Cheers, John

FYI - The transducers are both under the hood; not under the car.

Waste gate one is located below the MAF next to the air filter box. The EGR one is located next to the ABS on the opposite side.

Uh-oh... I spent an hour or two playing in the garage today, and have not isolated or fixed my problem. I "cleaned" the two vent filters as best as possible, since Phil doesn't stock them and the local dealership didn't have any in stock. The one for the turbo was especially dirty. I wound up swapping the two filter things, resetting codes, and going for a drive. No change -- same P0243 code when I stomped on it, and an obvious lack of boost while driving.

Following the suggestions here, I then swapped the two transducers, one for the other. I reset the codes, went for another drive. At first, I was pretty excited -- it sure felt like I was getting some boost at partial throttle and low (35mph) speeds. The car felt "right" off the line. Putting the pedal to the floor for a highway ramp, however, told a different story. Acceleration was poor, and I blew another CEL. I was hoping to get home and have the EGR error instead of the wastegate error.

No such luck. I'm still getting a P0243. I cleared it once or twice more. There's definitely some low-speed boost. But a hard acceleration throws the code. Also, if I'm cruising at 60mph and stomp it (kickdown switch and all) for a pass, pretty much nothing happens. The car downshifts, makes lots of noise, and barely accelerates. Somewhere in that sequence, the CEL comes on again.

So if it's not the filter and it's not the transducers, what do I look at next? If I've blown a turbo after all that transmission work six weeks ago, I'll probably start repairing this machine with a Sawzall and a dumpster. The honeymoon is definitely over! A V10 TDI is looking good to me right now...

Thanks for any more tips -- and the opportunity to vent.

Cheers, John

PS -- On the bright side, yesterday (Day Eight) brought electric power back to the house. :)

I'm not certain that "cleaning" the filters will be sufficient, but there is a way to test this theory. You could simply remove the filter from the wastegate circuit and drive it. If you still get the same symptoms then you can be sure the filter is not the culpret. Then, there are three possible problems; lack of vacuum to the circuit, bad wastegate actuator or defective turbo. I would say the defective turbo is least likely. You can check the actuator with a mity-vac (if you don't have one buy or borrow one) and can check the vacuum source with a vacuum gauge. I'd bet you have something simple, like a vacuum leak in the hoses between the source and the actuator - or a hole in the actuator diaphragm itself. Not worth taking a sawzal to it yet. Remember...it's an old car and rubber parts do deteriorate.

I tried driving with the filter removed altogether. A heavy-throttle highway speed pass still trips the same code. I can feel *some* boost, sometimes. However, there must be a safety/limp mode after the code is thrown, because the car just falls on its face after the dash lights up.

I have visually inspected the hose from the transducer to the actuator, and it looks alright -- still flexible, etc. I don't have a mighty-vac to test any better than that. I need to do an oil and filter change this weekend, if possible, so I'll get under the car and look at the actuator itself -- maybe it's just gunked up and cannot move freely. I'm ever-optimistic, but I'm pretty sick of driving this dog and throwing money down the hole to keep it running!

Thanks for any further tips/suggestions on troubleshooting this one. I don't know where to go from here.

Cheers, John

Search early posts by LARRY12, he resolved a similar issue. I believe it was a dodgy electrical connection to the transducer?

Sorry to dredge this one up again, but a 500-mile highway trip over the weekend shows that I'm not at all repaired yet. In the last 200 miles, my check engine light for the P0243 came on seven times. I finally just drove with my code scanner plugged in to monitor and clear it.

I have swapped the two transducers with no effect -- still get the code. I have driven with the filter completely removed -- still get the code. I can tell I get boost sometimes, but it is random and unpredictable. The wiring looks OK, but beyond seeing that it isn't frayed, I don't know how to check it. Long periods of heavy throttle -- such as a freeway entrance ramp or a long steep incline -- seem to be consistent at tripping the CEL. Shorter (stop-light) accelerations do not seem to trip the light.

So if you were going to start throwing parts at this problem, where would you start? After starting a hill at 70mph and cresting it at under 50mph, I realize this is not an optional repair on this car. Suggestions are very much appreciated!

Cheers, John

Have you tested the wastegate actuator with a mity-vac yet? That's what I would do next.

OK, over the weekend I finally had time and tools to look at this further -- using a Mity-Vac. When I connect the mity-vac straight to the wastegate actuator vacuum line, I can pull and hold a 27" vacuum for a good ninety or more seconds. When I hooked the vacuum gauge up to the vac line of the car and ran the engine, it was generating a steady 27" or so of vacuum as well.

So does this imply that it really is the transducer switch thingamabob? If so, that means both of mine are bad -- I already switched the turbo and EGR transducers in an earlier troubleshooting step. I may try to borrow one from a coworker that has a '99 year model, and see if I get the code using her transducer too. Maybe I actually have two bad ones, though I've never gotten an EGR code.

For what it's worth, I still only get the code under heavy load -- say, a steep hill at 75mph under throttle. Or accelerating from a stop to 70mph on a highway entrance ramp. When the CEL is not on, I regularly get some boost, but the car doesn't feel nearly as powerful as it did a couple months ago before all this started.

Thanks again for following the long, drawn-out issue. I'll continue taking suggestions at this point, and will update as I learn more. At least the cool fall air over the intercooler is helping pep things up!

Cheers, John

I've got one in the shop right now that is experiencing the same thing. The transducers look good. I'm going to look at it again but I do get some pretty rapid bleed off when I put vacuum straight to the wastegate diaphragm.

Answer
 

The waste gate diaphragm is damaged if it will not hold.