Range Rovers Forum banner

1 - 20 of 23 Posts

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #1 ·
I own a 2008 Range Rover HSE with 95k miles. Currently my RPMs dip to almost zero when the car starts about 50% of the time over the last 3 weeks. Otherwise the range drives great.
At 70k miles the check engine light came on and my mechanic cleared it after he cleaned the air mass sensor. Over the past winter the RPMS would drop and go up and down for 10 sec when the car started.This went away (mechanic told me maybe it is due to some bad gas.

About 1 month ago the check engine light came on due to p0420 (catalytic inefficiency bank1). Mechanic reset it and told me to come back so he can perform complete diagnostics.

Any thoughts on what is wrong? throttle body? air mass sensor, vacuum leak, ec?
 

·
Premium Member
Joined
·
2,467 Posts
Sounds like carbon fouling on the throttle blade. Many threads have addressed this, and there are some recommended repairs. Try a search for throttle body, and for induction.
 

·
Registered
Joined
·
687 Posts
I'am not 100% sure if this is the same problem as there is a TSB for a similar issue about the rpms dropping to zero on start up , but only when cold outside. The "power control unit" has to be updated , but as you're in new york and the temperature isn't dipping below freezing it could be a completely different issue.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #6 ·
so th p0420 code was erased a week ago. It was still there3 days ago and today it is not there. is that a good sign?
 

·
Premium Member
Joined
·
2,467 Posts
P0420/30 faults for cat efficiency only have one cause, degraded cat efficiency.

This can be a result of a failed cat, or can be due to something that is lowering the efficiency of the cat. Unburnt fuel and oil in the exhaust can do this. With the idle fluctuation, I would wager that your throttle body has a significant amount of carbon build up, and you may even see some standing oil in your intake, from a failed PCV valve.

Depending on recent service history, if your vehicle came through the door at my shop, with this fault, and your symptoms, I would recommend a full tune up, along with injection and induction cleanings, with the note that the cat may have irreparable damage, and may need replacement. I have seen some cats fail on these engines, but I have seen far more have low efficiency due to an outside source.

I have gone on about this before, and won't go into it too much, but these engines build up a lot of carbon, and over time this causes some serious issues.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #8 ·
I just checked the system voltage with the obd2 tool and it is either 12.5 (green) or 11.58 (yellow).... does this mean anything? I will bring to mechanic tomorrow but figured id ask. I bought the obd2 tool so i can scan and if there are any check engine lights i can search the forums..

Regarding induction and injection cleanings, do you think this i a must or is a throttle body clean, plug swap enough..Does my 2008 hse have a pcv? is it easy to have my mechanic replace?

THANK YOU SO MUCH FOR YOUR COMMENTS.... THEY ARE VERY MUCH APPRECIATED
 

·
Registered
Joined
·
2 Posts
I would start by cleaning the tb. Check the air filter if is dirty replace it and clean the air flow meter too. Other thing that could cause uneven idle is the breather valve on top of the right valve cover.r Someone mentioned that you live on a cold place, make sure your coolant mixture is fine. A software update might be require as well, but that is something that just the dealer or a independent land rover can do. Good luck!
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #11 ·
Regarding software update is this a common thing. I have a rr hse 2008 with 95 k miles. Last rover dealership service was at 60 k
 

·
Premium Member
Joined
·
2,467 Posts
The last software update for the engine system for this model to fix a problem was released about 4 years ago. There are no software fixes for your problems. The updates are purely to fix calibration errors that were not correct from the factory, and it isn't so much that they are common, but a lot of dealers used to be very quick to re-tune the PCM for all kinds of faults, so they got done a lot, even when not needed at all.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #13 ·
Thank you for all your help. I wish you were closer to ny. I have a great mechanic and want him to work on my car. However since he doesn't work on many rovers I'm a bit concerned. Can most mechanics perform drain and fill for basic fluids such as transfer gear, diffs, transmission. Or should I try to find a land rover specialist or just suck it up and go to a dealer.
 

·
Premium Member
Joined
·
2,467 Posts
Fluids are all pretty straight forward, just make sure the right stuff gets used(I would stick with LR fluid for the t-case) I've had a few issues with techs unfamiliar to ZF transmissions underfill them, but they're used in a lot of European cars, and all have similar processes.

To take care of the original issue, I would have a full tune up done, along with some cleaning services, but the plugs, PCV valve and ignition capacitor are all easy to replace that most mechanics should have no issues doing properly.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #15 ·
Instead of an induction and fuel injector cleaning , is it possible to add injector cleaner to my gas tanks a few times ... I guess I worry that things can get worst afterwards and right now it isn't so bad.
W
Also what is an induction vs injector cleaning?
Either way do you recommend adding an injector cleaner on a regular basis. Some
Land rover maintenance schedules recommend a conditioner with their services.

Finally, I checked the system voltage. What is it suppose to be? Sometimes it is green and other times yellow, so was wondering if the voltage is different for different cars.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #17 ·
Update
So today ran a diagnostics with a obd2 I purchased and no codes were found or pending. Does this mean my catalytic converter is ok? I had a p0420 code.
I still have the intermittent drop in rpm at start sometimes. Hoping to get this addressed. ASAP.

Thanks to everyone for all your help.
 

·
Premium Member
Joined
·
225 Posts
Discussion Starter · #18 ·
so this is my dilemma with the above.... i have a great mechanic but he doesn't do fuel injector cleanings as being recommended with an induction.
So in order for me to try to address my rough idle at start, and drop in rpm, (im also at 96k),id like him to perform a throttle body cleaning . but was wondering how seafoam works? would you recommend this as a first step... if this doesn't wrk, then ill bring vehicle to dealership for induction/injector cleaning......im hesitant about the inductin/injector cleaning since my brothernlaw is having issues with misfires/fuel rail pressures issues 20k miles after an induction/injecto cleaning.
 

·
Administrator
Joined
·
27,834 Posts
Your brother in law doesn;t own an L322 Range Rover either. Different cars respond differently to types of service. Even so, having issues 20K miles AFTER a certain service can hardly be blamed on that service.
 

·
Premium Member
Joined
·
2,467 Posts
If he is suggesting Seafoam instead of an induction, find another shop to have this service done, as he does not have the tooling to do this correctly.

Both have the same goal, however a proper induction service(usually BG brand, but there are others) is a gradual process, with a steady atomized misting/fogging of the chemical. Seafoam is a much more direct and heavily applied chemical, imagine the difference between being sprayed with a hose, and one of those misting fans on NFL sidelines at the beginning of the season. A full 12oz can of Seafoam is used in about a minute, a proper induction, with 22oz of chemical, takes near a half hour to complete.

I don't want to knock Seafoam, it is a good chemical, and compared to something like BG is far more DIY friendly, however it does not do the same job strictly due to design.

The injection service will help with overall drivability and responsiveness, and possibly help restore some lost power, however what it 'fixes' is not causing your current issues.

As stated in the linked posts earlier, be sure to have the PCV valve replaced, and engine oil changed immediately following an induction service, and spark plugs following an injection service.
 
1 - 20 of 23 Posts
Top