Engine system service required

[M-R-P]

I didn't realise how old this thread was!

[larshsm]

THREAD RESURRECTION ALERT!!!
...
So, as a last resort I reversed the direction of one of the one way valves on the VAC lines and, hey presto, airflow jumped to 15-16kg/h instantly! It has been OK for a week now so I think I have cracked it. It is an internal air leak which will never show up on a smoke test, so difficult to diagnose.
The valve I reversed was on the car in that position when I bought it, so has been wrong for a while.

Thought I would post just in case anyone else is having similar problems. Worth having a look if you are.

Cheers
Paul

Hi!

I also got the same problem of not being able to get more then 8kg/h through on idle. I got a 1999 S80 with a B5204T3.

Which check valve did you change direction of?

Worth mentioning is that I've been having trouble with a clogged catalytic converter that i now just recently got changed, and i got no error codes in VIDA. My MAF is also brand new.

[silverhorse]

Hi!

I also got the same problem of not being able to get more then 8kg/h through on idle. I got a 1999 S80 with a B5204T3.

Which check valve did you change direction of?

Worth mentioning is that I've been having trouble with a clogged catalytic converter that i now just recently got changed, and i got no error codes in VIDA. My MAF is also brand new.

Hello mate,

I changed the direction of the one nearest the MAF, not the one under the fuel injection rail. That's where they were on my engine anyway.
When you take them off, check that they actually work. You should be able to blow through one way, and as soon as you start sucking, it should close. If you can blow and suck, it's knackered. Check them both.

Hope this helps.....keep us posted!

Regards
Paul

[larshsm]

I could only find two of these valves, and both worked and were the correct way.

I've been monitoring different values i VIDA and besides the 8kg/h i also see that the injection time is about 1,7-1,8ms and the ignition angle is between around 20º to 27º BTDC (From VIDA: Normal value at idle speed between 0° and 20º before top dead centre (BTDC), and: Normal value with the engine at operating temperature at idle speed 2.0-4.0 ms )

It seems that the low injection time corresponds to the low air mass flow, but still i got normal (640-680 rpm) idle.


Anyone got any good ideas to this?

[jamesy12345]

I could only find two of these valves, and both worked and were the correct way.

I've been monitoring different values i VIDA and besides the 8kg/h i also see that the injection time is about 1,7-1,8ms and the ignition angle is between around 20º to 27º BTDC (From VIDA: Normal value at idle speed between 0° and 20º before top dead centre (BTDC), and: Normal value with the engine at operating temperature at idle speed 2.0-4.0 ms )

It seems that the low injection time corresponds to the low air mass flow, but still i got normal (640-680 rpm) idle.


Anyone got any good ideas to this?

new air filter?

[Harvey]

I would guess you need a new MAF or you have unmetered air getting in some how.

[larshsm]

new air filter?

I would guess you need a new MAF or you have unmetered air getting in some how.

Brand new air filter AND maf..

I have looked for leaks the easy way with spraying start gas all over the place and listening for engine speed changes and found nothing. The engine does sound a little harsh on idle i think, but then again I'm not used to the 5-cyl engines.

Could worn piston rings, worn inlet or exhaust valves, or wrongly installed timing belt cause these readings? What if one of the camshafts were to be a tooth wrong?

[silverhorse]

Reckon Harvey could be right with unmetered air.
Get yourself a smoke test done. There can be unmetered air getting in the system at a thousand different places and it will take you ages to stumble across the right place. Trust me, I know from bitter experience! Took mine to Volvo. £90 all in. Pricey BUT they know your engine, have the proper kit and you will have answers there and then.
Well worth it although you may need to spend lots to sort out what they find. I know I did.

[larshsm]

I went by the local Volvo dealer/garage today, and they told me that they don't have smoke testing equipment. I did speak a bit with a few of their mechanics, and they also though it could be a tooth wrong with the timing belt.

When i got home from work just now i popped off the covers for the timing belt, and i noticed that the three screws on the exchaust camshaftwheel seemed to have been set different before.



I think I'll go back out to properly see if the cams line up correctly.