2002 S60 Rough idle but smooth at higher RPM

draser · Post by **draser** » 20 Jan 2015, 09:19

To recap, we now have FT in single digits at OT, sensor 1 reading lambda 1, and sensor 2 switching too fast. There are no misfire and lean/rich faults after using car several days. The only code is the cat fault. If this is all correct your mixture and combustion are normal. The engine calculated load is higher than what I have pointing to an air flow issue. However, this is calculated based on rpm, tpf and maf. It would be helpfull to have data from a similar type engine to compare. But I can't explain why the load is 30% at idle, other than some flow restriction.

draser · Post by **draser** » 20 Jan 2015, 17:49

Well, if you're getting high trims at idle with engine hot, we're back to square 1. Can you have someone cover tail pipe w/palm and listen for hissing around exhaust flanges?

quietcoolone · Post by **quietcoolone** » 20 Jan 2015, 18:41

draser wrote:Well, if you're getting high trims at idle with engine hot, we're back to square 1. Can you have someone cover tail pipe w/palm and listen for hissing around exhaust flanges?

YES--- High STFT as soon as the engine starts and remain unchanged even after getting up to temperature.
Here is some recent data after resetting ECM
Startup and idle:
FUELSYS1 CL
LOAD_PCT(%) 20.0
ECT(F) 123
SHRTFT1 24.2
LONGFT1 -0.8
MAP (psi) 5.5
RPM 865
SPARKADV 13.5
IAT (F) 77
MAF (lb/s) 0.01
TP(%) 3.9
O2B1SV1(V) 0.675
O2B1S2(V) 0.035
Allowed it to idle 5min more hopping to see a drop in FT, but nada.
Went OT then quickly released pedal and got these numbers:
FUELSYS1 CL
LOAD_PCT(%) 24.7
ECT(F) 136
SHRTFT1 0.8
LONGFT1 -0.8
MAP (psi) 4.4
RPM 844
SPARKADV 10.9
IAT (F) 78
MAF (lb/s) 0.01
TP(%) 5.9
O2B1SV1(V) 0.505
O2B1S2(V) 0.735

Raised RPM to 2150 for 3 minutes and STFTL: -2.3, LTFT: 0.0

Will get someone to assist tomorrow with the tailpipe test, however i just coated the CAT Flange nuts and bolts with PB Blaster.

draser · Post by **draser** » 21 Jan 2015, 05:27

Your rpm is at 800 and it should be 600, ecu is adding fuel thinking it's still warming up. Are you at operating temp?

Post by **precopster** » 21 Jan 2015, 05:47

Let's not read too much in to that idle speed. My Denso B5244S P80 idles at 850rpm. (Same as this S60) The turbos are much lower. The NA S60 runs Denso engine management, cam sensor and MAF so are a different beast to turbos running Bosch.

One of the ETM firmware versions from Denso S60 will run my 2000 V70 happily so not really that unalike.

The main garage I did most of the ETM work for had very similar symptoms with failed ETMs. Misfires can be detected due to poor air supply but don't ask me why.

draser · Post by **draser** » 21 Jan 2015, 07:15

Good info, we need more of it for a NA engine.

quietcoolone · Post by **quietcoolone** » 21 Jan 2015, 09:31

draser wrote:Your rpm is at 800 and it should be 600, ecu is adding fuel thinking it's still warming up. Are you at operating temp?

Yes, There measurements were taken at 123ºF and 136ºF

precopster wrote:Let's not read too much in to that idle speed. My Denso B5244S P80 idles at 850rpm. (Same as this S60) The turbos are much lower. The NA S60 runs Denso engine management, cam sensor and MAF so are a different beast to turbos running Bosch.
One of the ETM firmware versions from Denso S60 will run my 2000 V70 happily so not really that unalike.
The main garage I did most of the ETM work for had very similar symptoms with failed ETMs. Misfires can be detected due to poor air supply but don't ask me why.

I agree. My 04' Turbo does idle at a lower (660 RPM).
The 02 S60 RPM drops to between 725-750, but only after it has been driven for a few minutes.

Please follow this sequence
This morning before taking off the CAT i decided to start her up. This time i just let her idle (did not touch the throttle)
Watch FT and Load numbers as engine warms up. (ECT)
FUELSYS1 OL
LOAD_PCT(%) 43.5
ECT(ºF) 51
SHRTFT1 -1.6
LONGFT1 5.5

FUELSYS1 CL
LOAD_PCT(%) 42.7
ECT(ºF) 59
SHRTFT1 5.5
LONGFT1 5.5

FUELSYS1 CL
LOAD_PCT(%) 39.6
ECT(ºF) 78
SHRTFT1 14.8
LONGFT1 4.7

FUELSYS1 CL
LOAD_PCT(%) 25.5
ECT(F) [ºF]95[/b]
SHRTFT1 25.0
LONGFT1 0.8

Removed dip stick and there was a loud hissing sound, idle got a lil rough (not too bad). it sounded like the air brakes on trucks or opening a tire valve. Correction: this was vacuum not pressure (out).
I also opened the oil filler cap and again the idle got a lil rough with the same hissing sound, -- as if the engine needed a place to breathe out.
Note: PCV was just serviced (including removing and cleaning the oil pan) and also plugged the hole for the turbo hose on the back of the engine (which stopped oil spilling out the engine at high RPM)
Soon after i put the oil filler cap back on, the idle was smooth again with these parameters:
FUELSYS1 CL
LOAD_PCT(%) 26.7
ECT(ºF) 143
SHRTFT1 -0.8
LONGFT1 0.8

I can't tell if there is any relationship between LOAD PCT and Fuel trims, because the LOAD PCT at startup was 43.5 and STFT was -1.6, and LOAD PCT started to drop while FT were going positive. It was only after the oil filler cap was opened (for air to go in) that these parameters dropped [LOAD PCT 26.7, STFT -0.8]

I wonder if there is still an issue with the PCV system. I say this because of the huge amount of vacuum at the dip stick/oil filler cap until everything settles, then there is some smoke.

Any ideas what i should do next?

Post by **precopster** » 21 Jan 2015, 13:55

I just serviced the PCV on a 99 V70 NA and turned pressure into suction at the dipstick. It now makes a hissing sound when you remove the dipstick. Are you certain it isn't suction at the dipstick? Glove test at dipstick? Oil cap is not the place to test.

Now that I see that there's 300k miles on this beast the PCV pressure can be a result of worn bores. There may be no quick fix. My 1993 960 had MASSIVE PCV pressure and was unfixable with PCV service.due to worn bores.

quietcoolone · Post by **quietcoolone** » 21 Jan 2015, 16:20

precopster wrote:I just serviced the PCV on a 99 V70 NA and turned pressure into suction at the dipstick. It now makes a hissing sound when you remove the dipstick. Are you certain it isn't suction at the dipstick? Glove test at dipstick? Oil cap is not the place to test.

Now that I see that there's 300k miles on this beast the PCV pressure can be a result of worn bores. There may be no quick fix. My 1993 960 had MASSIVE PCV pressure and was unfixable with PCV service.due to worn bores.

A little history:
When i first serviced the PCV there was a loud noise coming from the front of the engine that would go away when dipstick was removed. I serviced the PCV for a second time and this time i removed the oil pan to ensure the oil return was completely clean. Put everything back together and that noise has not come back, however today (for the first time) after warmup and removing the dipstick there was a great amount of [Correction] vacuum as described in prior post (not pressure)-- same issue from oil cap.
Once the Vacuum was released the car ran great with no pressure at dipstick -- [/b](there was little smoke)
My thoughts area if the bores were worn, this issue would occur at all times-- and this is why it makes it hard to diagnose.

draser · Post by **draser** » 21 Jan 2015, 17:36

Can you remove the intake end of hose coming from pcv and see if pressure at dip stick goes away?

2002 S60 Rough idle but smooth at higher RPM

Re: 2002 S60 Rough idle but smooth at higher RPM