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L322 4.4 M62 rough running

4K views 30 replies 11 participants last post by  boxster964 
#1 · (Edited)
My 03 4.4 petrol engine misfires. Idle is pretty good and stable at 600 rpm.
When increasing revvs I can hear the engine missfiring on the exhaust note and also the rpm is somewhat unstable.
When accelerating I get a bad vibration. More noticable when engine is warm. There are no fault codes. No air leaks. Every engine gasket is new, checked with smoke machine and starter fluid spray.
Parts changed:
Timing chain assembly
Vanos seals rebuilt
All 8 coils (new Hella coils)
Spark plugs.
CCV system replaced.
Front O2 sensors replaced (Bosch)
New fuel filter.
Rear O2 sensors replaced (Bosch)
MAF replaced (Bosch)

idling the MAF reading is 19,2 kg/h. If I unplug the MAF, engine stalls imidiatly. Running it without MAF the revvs are a bit more stable, but can still hear missfire through exhaust.
Camshaft position sensor values are resonible on both banks.


the small hose running from the air pipe between MAF and throttle body, where does that go? Big one goes to the airhose for the power brakes, but what about the small one.


Anyone have any input on What to do next?
 
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#2 ·
sounds like you've a fair amount of time troubleshooting already. have you done a compression/leakdown test yet? verified good fuel? injectors tested?

I realize you've done a smoke test, ignition parts replace, etc. but this still sounds misfire related. can you confirm you have an OEM grade MAF, O2, etc? I went through this pain a couple of years ago with an M62TU and it came down to replacing cheap parts and sealing a sneaky leak at the air filter.
 
#7 ·
No, bone dry. I rebuilt the engine when changing the chain. All new gaskets, 32 new lifters, valve seals, cylinder walls looked good, no oil consumption either.
After more testing I notice big increase in vibration the warmer the engine is. On cold drives it really is not that bad.
 
#13 ·
Coolant temp is 104-109 Degrees C when driving. But radiator coolant temp is only 15-28 degrees. After driving 20 min the upper hose is hot, but the lower radiator hose is cold.
Do the ecu use radiator temp sensor to manage fueling? If so the engine might get to much fuel when warm.
the termostat is only 3 months old, OEM from BMW dealer.
There is winter now, but I would think a big V8 would get hot enough to open the termostat regardless?
 
#14 ·
The misfire is probably a weak coil or cracked insulator, allowing un-burnt fuel to get into the exhaust. If it's only misfiring on one side you could swap the coils and plugs from one side to the other to find the bad coil or plug. You need to solve the misfire before anything else.

I suspect you have 2 problems at the same time, misfire and leak. A leak in the PVC circuit might not show up on a smoke test, because it is under positive pressure not vaccum.

The exhaust blow-by gases in the crankcase have little to no oxygen. The PVC gas is mixed with the intake air to reduce the oxygen percentage going into the cylinders, then the ECU can reduce the fuel lower than what it could do with fresh air alone, and keep the at a mixture ratio proper. This ECU gets no feedback from the PVC system, it assumes it is working correctl. So the ECU cannot compensate PVC issues, often throwing codes for other systems. BMW should have put a pressure sensor in the PVC system to diagnose these issues.
 
#15 ·
if you had the intake off you should have replaced all the silicone seals and the PVC plate and the rubber vent hoses.
NOTE a key that the PVC plate is bad is when you start seeing oil leaking from the cam covers or the spark plug wells start filling with oil,
or you have large plumes of the white smoke as soon as you start the engine.
NOTE this will usually start after a few below freezing starts where the water vapor in the blow by freezes and kills your PVC plate
 
#20 ·
Update on this dreaded misfire.
Found small leak in pipe between MAF and throttle body. Fixed. No change.

Cleaned throttle body. No change. Pin 4 and 6 reads 4.5 ohms. Rises linear as I open the throttle blade.

Replaced MAF with new Bosch, no change.

Replaced both rear o2 sensors with new Bosch. No change.
Looked over PCV, all looks fine.

Air mass at idle is 19,4 kg/h and 5,8 g/s according to my iCarsoft diagnostic reader.
The vibration is bearly noticable when engine is cold and gets worse the hotter the engine gets.
performance on full throttle seems fine, pulls hard but vibrates slightly on and off.
 
#23 ·
Seems like the same problem I am facing with my 2005 L322 M62B44.

Started with Trans Prog Failsafe message, and then a plum of thick white smoke, RPM idling erratically, loss of power moving upslopes, the whole frontal engine bay is shaking vigourously like a 6.1 earthquake.

Here is the list of parts I have changed till date:

1. PCV Crankcase Ventilation Oil Seperator LR003814
2. Breather Hose
3. PCV Valve + Gasket
4. Neutral Safety Switch
5. 8 x Spark Plugs (Champion brand) LR021006
6. 8 x Ignition Coils (HJL Taiwan Brand) LR022494
7. 2 x Engine Valve Cover Gaskets (Original LR)

Plum of smoke has disappeared.
Engine idling is slightly more stable.
Power returning to the wheels.
Misfiring is still felt at times, with a thud at lower RPM, as if some car just hit you from the back bumper.

I have a in-house mechanic who swings by my place to work on replacing parts, and testing the ride.

I hope you solve your problem soon.

This M62 engine is starting to rattle my nerves, but I am trying not to fall out of love with my Rangie. I am just taking my time, and money, and mo' money to fix this beast until she can ride with me till death do us part. BMW engine + setup is really such a pita.
 
#24 ·
You should have replaced the intake manifold gaskets (orange in the pic) when you were in that deep. Mine were hard as rocks, and not making a good seal.

Note you can hinge up the intake on the passenger side. The manual says to remove all connections, but that's to replace the intake. To get access you only need to disconnect on the driver side.

If you are having overheating issues, also change the valley pan cover. The line of bolts under the heater pipes. That was the source of my overheating problem I struggled to find for over a year.


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Seems like the same problem I am facing with my 2005 L322 M62B44.

Started with Trans Prog Failsafe message, and then a plum of thick white smoke, RPM idling erratically, loss of power moving upslopes, the whole frontal engine bay is shaking vigourously like a 6.1 earthquake.

Here is the list of parts I have changed till date:

1. PCV Crankcase Ventilation Oil Seperator LR003814
2. Breather Hose
3. PCV Valve + Gasket
4. Neutral Safety Switch
5. 8 x Spark Plugs (Champion brand) LR021006
6. 8 x Ignition Coils (HJL Taiwan Brand) LR022494
7. 2 x Engine Valve Cover Gaskets (Original LR)

Plum of smoke has disappeared.
Engine idling is slightly more stable.
Power returning to the wheels.
Misfiring is still felt at times, with a thud at lower RPM, as if some car just hit you from the back bumper.

I have a in-house mechanic who swings by my place to work on replacing parts, and testing the ride.

I hope you solve your problem soon.

This M62 engine is starting to rattle my nerves, but I am trying not to fall out of love with my Rangie. I am just taking my time, and money, and mo' money to fix this beast until she can ride with me till death do us part. BMW engine + setup is really such a pita.
 
#25 ·
Thank you lattyak.

I will get my mechanic to look into replacing the intake manifold gaskets.

Any more parts to replace besides the valley pan cover?

I don't think my instruments are getting the right readings, as the engine is consistently throwing out high temps. Will have to look into the fuse, and the temp gauges soon.

I just replaced the radiator just over a month ago, and the lower radiator hose as there was a leak.

Thank you for your recommendations.
 
#27 ·
Thank you lattyak.

I will get my mechanic to look into replacing the intake manifold gaskets.

Any more parts to replace besides the valley pan cover?

I don't think my instruments are getting the right readings, as the engine is consistently throwing out high temps. Will have to look into the fuse, and the temp gauges soon.

I just replaced the radiator just over a month ago, and the lower radiator hose as there was a leak.

Thank you for your recommendations.
valley pan replacement usually coincides with cooling system refresh (water pump, colder temp thermostat, hoses), fan clutch/blade and an intake reseal. spark plugs/coils if these were never done. it costs more in parts but will save you tons of $$$ further down the road in repeat labor.
 
#26 · (Edited)
Really been challenging to fix this issue.
Replaced spark plugs with recommended NGK BKR6EQUP. Small misfire from 1200 to 2000 rpm now gone.
Tried new genuine crank position sensor. Made no difference.
I actually think engine is good now and that this vibration/shudder is drivetrain related.
Replaced rear differential, sadly no difference.
It has become so bad now when the car is warm after 15-20 min driving that stop and go traffic is really uncomfortable.

Can the transfer box make bad shudder? Is the Castrol BOT oil essential? Run high quality 75/85 Volvo gear oil now.
Read through this and it looks like the oil is superduperspecial..

really hope it is not gearbox, because one month ago I had it out and replaced TC and oil/filter. Lock up vibration when lock up engages dissapered after this.
These trucks are full of issues after many years and miles.
 
#28 ·
Replaced spark plugs with recommended NGK BKR6EQUP. Small misfire from 1200 to 2000 rpm now gone.
Thanks RoverLars, my new Champion spark plugs may still be causing the intermittent misfires. I hope not. I will look into buying a set of NGK BKR6EQUP Laser Platinums to replace and evaluate once again.

Don't mean to hijack your thread btw. Just sharing my current similar predicament...

You kind folks are way more technical than I can ever be :)

valley pan replacement usually coincides with cooling system refresh (water pump, colder temp thermostat, hoses), fan clutch/blade and an intake reseal. spark plugs/coils if these were never done. it costs more in parts but will save you tons of $$$ further down the road in repeat labor.
Cheers dlimanov, will pen down this list.
 
#29 ·
when the valley pan is replaced,
also remove the rear water bridge and replace the gaskets that seal it to the rear of each head,
and replace the short coolant hose that connects the bridge to the firewall pipes.
also fit new PIPE O rings use DC111 on all the rubber o rings this will keep them soft so they dont leak .
Get a new valley pan,
dont try to use sealant to reuse the old one the chances are very Hi this will leak
 
#30 ·
dont try to use sealant to reuse the old one the chances are very Hi this will leak
And it's another case where it's really probably not worth the little bit you'd save.
A good replacement is $50 from Rock Auto. I replaced mine with the Uro valley pan a few years ago, and haven't had any problems with it.
More Information for ÜRO PARTS 11141742042PRM (rockauto.com)

And of course don't forget new seals for the valley coolant pipes, front & back.
 
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