94 855 turbo suddenly lost power.

[calbrit01]

So I was just overtaking on the freeway when I suddenly lost power. Managed to limp off the freeway barely doing 40. Felt like a serious misfire, or not enough fuel - similar to the feeling you get when you run out of gas, i.e accelerating makes the engine die. After I had stopped, I could start the engine, but if left to idle would hunt for a bit and then die. Sometimes it would rev up but with a new whining noise ( maybe my imagination), sometimes revving would just makes it run really rough. Any ideas?

Thanks

SAL

[Ozark Lee]

Pull the codes from port A-2 and check the fuel pressure at the end of the rail.

How fresh are the spark plugs and what kind are they?

...Lee

[calbrit01]

Thanks Lee, Plugs are new within the last 12 months - Cant remember think they were the Bosch coppers - anyway, they were the ones recommended on this forum, and gaped correctly. Also new are the leads, distributor,rotor,CPS, rear O2 sensor (newish),alternator,timing belt and all bits (including water pump). I am seeing posts about Throttle body sensors, MAF sensors, and ETMs as possible issues for these symptoms. I had to take it in to the mechanic, but want to be able to discuss with him, and make sure I am not taken for a ride...

Thanks

SAL

[calbrit01]

So this was unexpected, mechanic says Turbo Intercooler hose was blown. Hopefully that was it.

[Ozark Lee]

I have not used these but they seem to have a great reputation.

http://www.stylinmotors.com/volvo.html

...Lee

[StarmanDXE]

I am seeing posts about Throttle body sensors, MAF sensors, and ETMs as possible issues for these symptoms.

Is there a TB sensor in these cars?

Could be the MAF... Try cleaning it off with some MAF cleaner? Also, in my car, the connections to the MAF were super corroded and the engine could be killed (from an idle) by pulling on the cable.

ETM is only in '99+ cars and was an issue in various models from '99~'02 (or '03).

My car was having intermittent misfiring issues and I had no luck finding the problem. Thought that the corroded MAF connectors was it, but it wasn't. Didn't have any more time to mess with it and ended up taking my dad's car back to school (for the time between Thanksgiving and Christmas). He took the 850 to a mechanic and they said the Cam Position Sensor (CPS) was bad. Everyone else said CPS going bad has only ever manifested in a problem with starting, not with misfiring. I found it strange that this was the answer, but very believable (and the car seems to be running great!) So, perhaps check your CPS. It could have taken a more extreme dive than mine did.

So this was unexpected, mechanic says Turbo Intercooler hose was blown. Hopefully that was it.

Edit: Ha! Somehow I glossed over that... Hope that's the fix!

[MadeInJapan]

Yeah, it happens so often...these hoses get old and soft from oil (from condensed exhaust) running through them, then they may even freeze from moisture condensation...you hit the turbo hard and "boom!" You can buy the Volvo hoses, but to be honest, if I had a hpt (high pressure turbo), I would replace with either Samco or Stylin' silicone hoses and use "T-clamps" on them so they never blow off, even when their interiors get slick.

Btw, when my intercooler cracked, they were the exact same symptoms as described above...the air/fuel mixture gets totally screwed up...even limp mode doesn't quite work and the engine will die. The only way to drive the car home is to pull the MAF sensor connector so the ECU realizes that a sensor signal is missing and forces the car into limp mode.

Glad you got this sorted out, calbrit01!
For all of those others watching this thread, I've read now twice in 2 days of a turbo hose issue. If you car is 10 years old or more, by all means squeeze these hoses to see how they're holding up. Nothing worse than to be stuck far away from home with no place for replacement parts...Same goes for the vacuum hoses...seems that when these go bad, they almost always make the owner think there's a bad 02 sensor when it's not.
-MIJ

[calbrit01]

Ok, I can confirm it was only the Turbo Intercooler hose (this time, lol). Also, the throttle body was clogged, so was cleaned out. Nice to know the trick with the MAF.

I did have some interesting observations:

Had the CPS replaced last month as the car was dead. Immediately after the car went like a rocket, but I noticed it was over boasting sometimes. The mechanic said it could be the vacuum hose from the turbo to the fuel pump (cuts fuel when overboast occurs apparently). So as I keep having to fix vacum issues I ordered the silicon kit.

I also was having a problem cold starting - Separate topic.
So next , the turbo hose blows. After replacing, the power is not as it was immediately after the CPS replacement - not bad, but not epic ( just seem to have to push harder on the accelerator ). First cold start this morning after hose replacement - down from 7-10 seconds to 3 seconds.

So I guess I have a further question as to what is an expected level of performance, and was my brief "enhanced performance" due to the hose giving out ( hence the overboost)? I know its a difficult one to answer without HP output figures to compare, but would be interesting to know if sudden extra boost is an indicator of an issue?

Thanks

SAL

[MadeInJapan]

Believe your car is suppose to boost about 8 or 9 psi without being chipped or upgraded... so, what you were experiencing before might indeed have been over- boost. However, if you're concerned, you can disconnect the battery for 10-15 minutes to reset the ECU's adaptives....just make sure you have your radio code.

[calbrit01]

Thanks MIJ,

I spoke to the mechanic, he said that as it was intake pressure that was altering due to hole in the intake hose, over boost was quite possible. He did reset everything according to the service sheet, so I think I am good. I guess I got exited thinking I had a whole new car. Ah, well less power will keep me out of trouble,