P38A MOT today it failed

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Colin from Hull

Active Member
Posts
299
Hi
Took my 1997 4.0se range Rover for it MOT today failed on some small things.
1 Rubber Boots on tracks Rods ends, plus another boot
2 The indicator light on my fog light switch......how do I remove this switch
3 This is the nightmare one Emissions.....said its miles out.
What is the procedure in checking the variables regarding my emissions, the guy said I had a pattern exhaust on which can effect the back pressure compared to an original one. I do have a blowing joint which I will sort.
Now just a bit of history.....I had this problem a couple of years ago only firing on 7 cylinders but a mate of a mate manage to pass it, a head gasket eventually went. Over a few months did the head gasket which I thought would solve the emission problem....
 
The blowing joint can mess your emissions up.
If it's only running on 7 or you still have a misfire or other ignition problem then that's not going to help.
I wonder if your 'mate of a mate' - assuming he's a tester or knows a bent one - just hooked another vehicle up to the machine & entered your car's details before running the emissions test.
I'd suggest sealing your system properly & running a diagnostic to see if any faults are shown.

If you have cats pattern cats can also be a PITA, often only good enough to get through an MoT straight after fitting & being useless the following year. Not just my opinion but that of the testers I've used for all our tests for years.
Have experienced this on Pug 306.The pattern cat was about half the size of the genuine but needed to use a pattern as my eldest had forgotten his test was due until I rang him at Uni & it failed at a centre local to him on emissions as there was a split in one of the pipes on the original genuine one. I wasn't in a position to repair it & had to fit a cheapie pattern. The pattern failed badly on emissions the following year. I'd welded the original during the year & refitting it saw the emissions down to virtually zero & an easy pass.

Was the car up to full running temp at the time of the test? I take ours for a good run before arriving at the test centre so everything - incl cat(s) - is at normal temp.
 
Hi
Just left the vehicle outside the night before, so unless he took it for run (which I doubt) the garage would have tested in the morning. Running on 7 was a couple of years ago and I have done the head gaskets since then, hence me thinking it would have been ok this time. The garage suggested starting with a compression test, then ignition systems, injection system, exhaust. It hasn't had many long runs so maybe a bottle of Catclean
 
What did it fail the emissions on? CO/HC/Lambda? Guess it's CO but best to check
 
Notwithstanding the exhaust leak if it was cold & just left to idle for some time I'm not surprised if the emissions were off.
As you say the 7 cylinder issue was a couple of years ago, what were the figures like last year when I'm assuming it passed?
 
Fix the little bits sort the blowing exhaust take it for a proper drive n get the cats working then put it in for retest.......don't stress it. Mine had lower emissions on aftermarket cats.
 
hi
This is the first MOT since doing heads.
What should compression values?


These are the emission values.
Fast Idle Test
Engine Speed 2450-3050 rpm
CO =< 0.3% 3.88% FAIL
HC =< 200 ppm 159ppm PASS
0.95 - 1.09 0.919 FAIL

Second Fast Idle Test
CO 3.72 FAIL
HC 189 ppm PASS
0.920 FAIL

Natural Idle Test

Engine Speed 450 - 1050 rpm
CO =< 0.5% 3.28 % FAIL
 
Hi
On front of failure sheet it states the following.
Exhaust carbon monoxide content after 2nd fast idle exceeds defaults limits
Exhaust lambda reading after 2nd fast idle outside specified limits
Exhaust carbon monoxide content at idle exceeds default limits.

What will cure these?
 
brianp38dse said:
looking at those readings they were getting lower, engine needed a good run to warm up.
Click to expand...

+1 - my thoughts exactly.

Colin from Hull said:
Hi
Good idea long term but could do with a solution within the 14 days which started on the 8th Oct.....
Click to expand...

Sorry, but take it to an MOT station with a brain - I'd highly suspect, given what the readings show that it was simply too cold, and therefore on a rich mixture ... what was the oil temperature ? or did the tester bypass that bit of the test ? ( don't ask me how I know about this bit :rolleyes: - YMMV)

IMHO, ONLY go to a test station where you can at the very least accompany the vehicle AND it has had an italian tune up as close as possible (in time) to the emissions test....

The cynic in me might suggest that your "garage" might offer you a few quid to "take it off your hands" or somesuch :rolleyes::mad:
 
I'd be surprised if warming the engine up fully would make a huge difference, unless it was stone cold when the emissions test was done. The exhaust blow could be causing the lambda issue. Plugs/dizzy cap/rotor arm etc could all help with the CO as its most likely caused by a slight misfire even if it's not really noticable
 
The garage was quite helpful, giving lots of maybe's what could be wrong, he did say to take to a garage with the equipment to read what's going rather than guessing and start buying sensor's.
I do have some Blackbox Solutions software, would the Gems Engine package read everything and help solve the emissions.
 
Hi
I do have the Blackbox Gems Module.....can someone help me with what I should be looking for when reading the various information.
 
Sounds like it is running rich, depending where the blow is it could think there's more air in the mix and dump more fuel in to compensate, get that blow sotyed first. Whats your mpg like? Check the fuel trims in nanocom. Did you get it running properly, i.e all 8?
 
Thanks....
Will sort exhaust blow first, what sort of reading such I get from the lambdas if right or wrong?
I have Rovacomlite......haven't used it much other than EAS.
It seems to run ok so I would say it running on all 8.
I will check plugs tomorrow, air filter, the price range for sensors is wide.....do you get what you pay for?
Any advice on a good make etc...
 
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