Increased engine NVH when at operating temp

**str405** · 5th July 2022, 09:38 PM

G'day all,

My 2007 TDV6 D3 seems to increase in NVH levels when it is at operating temp.

Seems to run smooth and quiet when cold and slowly gets rougher and noisier when approaching and finally reaching temperature.

All I can think is that there is an exhaust leak somewhere which is not catastrophic, but enough to manifest only when it has heated up sufficiently to allow gases to escape.

Has anyone else experienced this? What was the eventual fix?

Have had the crossover pipe replaced with new one recently by dodgy mechanic (turned out to be a 'broker'). Don't want to go back to him to diagnose.

had fault code P023D-22 (6C) Manifold absolute pressure - turbocharger/ supercharger boost sensor A correlation - general signal failure appear several times, but not so often recently and have not had for a while now. Have had other similar codes ('message failure/ General Electric failure') but not consistently.

Battery is fine - But how would this affect NVH at operating temp?

Troubleshooting thoughts short of having a reputable Specialist look into it? Located CBR.

**BradC** · 6th July 2022, 12:57 PM

Have you looked at your injector balance values cold and hot?

I have one injector that starts out good when cold and progressively gets worse as it warms up.

Starts out ~980 and by the time it's really warmed up it's down to ~770.

I can feel / hear the difference.

**str405** · 6th July 2022, 02:26 PM

Originally Posted by BradC

Have you looked at your injector balance values cold and hot?

I have one injector that starts out good when cold and progressively gets worse as it warms up.

Starts out ~980 and by the time it's really warmed up it's down to ~770.

I can feel / hear the difference.

Thanks for your response Brad

I was glad you mentioned...

I did so happen to check these both cold and hot. The right bank of injectors is very low, see below.

When Cold

Injector 1 = 1074
Injector 3 = 1064
Injector 5 = 1080

Injector 2 = 875
Injector 4 = 909
Injector 6 = 989

When Hot

Injector 1 = 1209
Injector 3 = 1272
Injector 5 = 1143

Injector 2 = 757
Injector 4 = 745
Injector 6 = 865

Will try Liqui-Moly fuel system clean + injector clean + fuel filter change soon.

Have you looked into rectifying your problem injector? Solved the issue?

Why would an entire rail be low pressure?

**BradC** · 6th July 2022, 06:57 PM

I've been discussing options for injectors with the accounting dept while we've been away and as yet haven't come up with a conclusive decision.

Are your readings injector numbers per the GAP or are they injector numbers per the LR documents? They are different.
https://www.aulro.com/afvb/attachmen...bering_new.pdf

I believe my current options are :
- Shotgun replace all 6
- Pull all 6 and get United Fuel Injection to clean/test them then replace any deemed out of tolerance
- Buy one and take a punt on replacing just the one that appears duff.

I'd like to do a spill test, but I don't have the kit and given the age of the vehicle I'm not convinced I'd get all pipes out and back without breaking one. If I replaced all 6 I'd do the return lines also. In my case, the other 5 are between 950 & 1050 mostly, so it's really only one outlier.

**350RRC** · 6th July 2022, 07:32 PM

Originally Posted by str405

Thanks for your response Brad

I was glad you mentioned...

I did so happen to check these both cold and hot. The right bank of injectors is very low, see below.

When Cold

Injector 1 = 1074
Injector 3 = 1064
Injector 5 = 1080

Injector 2 = 875
Injector 4 = 909
Injector 6 = 989

When Hot

Injector 1 = 1209
Injector 3 = 1272
Injector 5 = 1143

Injector 2 = 757
Injector 4 = 745
Injector 6 = 865

Will try Liqui-Moly fuel system clean + injector clean + fuel filter change soon.

Have you looked into rectifying your problem injector? Solved the issue?

Why would an entire rail be low pressure?

You've nearly answered your prob.

DL

**str405** · 2nd August 2022, 02:39 PM

Update:

Have been monitoring Injector pressures - no changes after several bottles of LiquiMoly injector cleaner and a new filter

I have since had a new fault raise its ugly head - P2290 injector control pressure too low. high coolant temps and high oil temps coincided with this fault, as well as low engine power under load and a noisier engine at all speeds, loads and rpms.

I would have thought that an 'injector control pressure tolerance exceeding limits' (or similar) fault would have shown up. If I'm not mistaken I think P2290 is often related to the LPFP or HPFP. I note however that the HPFP has been replaced about 40,000km ago and live tracking of HPFP pressure shows that it is functioning as expected.

I will test the pressure at the schrader valve when a pressure test kit comes in, but could a LPFP fault cause injector pressure balances to skew (three are currently high >1300, other three <800, but within limits according the the ECM as no fault codes have shown for this) as well as rough running and high coolant and oil temps? Has anyone else experienced this or are aware of similar occurring?

I don't want to be replacing injectors if a LPFP is the culprit.

Paul

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