2001 V70 2.4T Oil pooling in the wells around ignition coils, Permatex 51813 cam sealer Topic is solved

[abscate]

It's a late 2005 replacement ETM, fwiw

[prwood]

So... I found something else that just MIGHT be an issue. I am honestly not sure how long it has been like this, but here's what happens if you squeeze the ring around the edge of the charge air pipe at the throttle end:

HEY NOW

When fully reassembled, this results in a gap right at the joint between the pipe and the throttle body, particularly if any pressure is applied to either the throttle or the pipe:

A Gap

I'm guessing this isn't helping things, and is maybe even the source of these issues? I'm not sure at what point this happened, but it doesn't seem like it would have taken much for it to happen... maybe the hose clamp was overtightened and cut into the plastic... or the tightness of the plastic being clamped to the throttle, combined with movement creating excessive force on the joint in the plastic...?

In any case, it seems like this could cause issues with air flow? But would it also cause the P0121 TPS code?

Bear with me while I ruminate. In my mind I am comparing it to the effect you get when you put two straws in your mouth, with one in a drink and one out in the air, and you can suck up very little, if any, of the drink. In this case the throttle would be the mouth, the charge air is the drink, and the ambient air in the engine is the air outside of the drink. So the throttle would be getting very weak gulps of air. I am wondering if this would trigger the TPS error detection programming to think there was an issue: Based on the mass air flow sensor reading and the position of the throttle, the computer knows how much air to expect through the throttle at any given time. if it requests the throttle to open to a certain position and sees less than the expected amount of air (due to the gap in the charge air pipe), perhaps it thinks that the the throttle position sensor is not reporting the correct value, and therefore overrides the throttle position to a fixed 20%, and sets the P0121 code indicating that there is a problem with the TPS.

Sound reasonable?

Whether or not this is actually what's happening, I should probably still do something about the gap in the pipe. Do you suppose it's the kind of thing that a bit of duct tape would fix, or perhaps some epoxy? Or would I be better off trying to find another charge air pipe at the junkyard or some such?

[RickHaleParker]

Do you suppose it's the kind of thing that a bit of duct tape would fix, or perhaps some epoxy?

• Clean crack with rubbing alcohol, let dry.
  Place a thin bead of Super Glue Gel on the edge of crack.
  Push crack together.
  Sprinkle Baking Soda on Super Glue.

Cures and harden in ~5 seconds with a bond 5 times stronger then slow cured Super Glue.

The crack is allowing unmetered air to enter the engine, The ECM thinks the engine is less air then it is, that would throw off the Air/fuel calculations towards a lean mixture.

[jonesg]

Throw it away.
Make sure the new one is properly supported.

[abscate]

Do you have a OBD reader that can give you Short Term Fuel trim (STFT) readout?

That can help diagnose a vacuum leak really quickly.

In BOS next week if you don't...

I can bring my spare charge air pipe too...which I just found looking for a part for my Albany colleague.

On edit - got it wrong - I have the air pipe from MAF to Turbo spare, not the TB charge air pipe.

YES - unmetered air will totally mess up your car running and drive lots of codes. If you have a few minutes, you can turn car off, unplug your MAF, then try driving it locally and see if it improves (you will get a code for MAF error doing this, of course). What this does is forces the ECU to drive off a stored rpm/fuel map to determine fuel which works pretty well, except it runs rich to protect the engine.

[prwood]

Throw it away.
Make sure the new one is properly supported.

Properly supported... meaning?

[prwood]

Do you have a OBD reader that can give you Short Term Fuel trim (STFT) readout?

That can help diagnose a vacuum leak really quickly.

In BOS next week if you don't...

I can bring my spare charge air pipe too...which I just found looking for a part for my Albany colleague.

I do, in fact, and I thought it was odd that both the STFT and LTFT were reading ZERO. I assumed it was because the throttle was malfunctioning and locked at 20% and therefore no fuel trim adjustments could be made.

[prwood]

I can bring my spare charge air pipe too...which I just found looking for a part for my Albany colleague.

Assuming it's in better shape than mine and is the same part #, that would be awesome. PM me to arrange a date and time.

In the meantime, I'm looking at making a temporary repair just to confirm whether fixing the crack makes the current problem go away.

[abscate]

I think this is a 50-70 part new from our vendors - you owe this car that for your last trip

Sorry about the excitement of a free part - corrected above.

parts numbers - you might have to be careful with engine number and mid year changes on this part

Screen Shot 2017-12-08 at 9.00.07 AM.png (206.07 KiB) Viewed 1338 times

[prwood]

I think this is a 50-70 part new from our vendors - you owe this car that for your last trip

Sorry about the excitement of a free part - corrected above.

parts numbers - you might have to be careful with engine number and mid year changes on this part

Yup, I was looking at this earlier today. Might stop by my local dealer to see if they have it and what their price is. Boston Volvo Village's web store has the one I need for $75:

31101214

https://www.bostonvolvocarsparts.com/p/ ... 01214.html