Nerd job of the week.

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Burnerman

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Brimming with self confidence, I demonstrated how to check for a leak on a neighbours cars exhaust - namely by putting the palm of my hand against the tailpipe and listening for the hiss.
(52 plate Pug 206 1.1)
It was with a certain disbelief that there was a huge bang, and the post cat lambda sensor blew completely out of the catalytic converter :eek:
'Errr sorry mate but as you can see its rusted away' says I.
Two hours later, one new cat and 2 lambda sensors (£200) we are pals again :p Not much profit on that one :D
Hands in pocket from now on :p
John :)
 
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That really is rotten luck mate! As Mursal says, we've all been there, but you do your best to help someone, it bites you in the proverbial and you do end up wondering if there is a God!

Presumably your neighbour isn't really mechanically minded (or you'd not have been demonstrating the technique in the first place)? As such, I bet he'll not believe that if it was rotten enough to blow a lambda sensor out of its hole with the few miserable PSI that can be generated by hand, it was shot anyway!

There really is no justice.

If it makes you feel any better, I too am "sharing your pain", having just re-arranged the front subframe on my beloved (i.e. old and impossible to find parts for!) Alfa this afternoon!
 
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Burnerman said:
Brimming with self confidence, I demonstrated how to check for a leak on a neighbours cars exhaust - namely by putting the palm of my hand against the tailpipe and listening for the hiss.
(52 plate Pug 206 1.1)
It was with a certain disbelief that there was a huge bang, and the post cat lambda sensor blew completely out of the catalytic converter :eek:
'Errr sorry mate but as you can see its rusted away' says I.
Two hours later, one new cat and 2 lambda sensors (£200) we are pals again :p Not much profit on that one :D
Hands in pocket from now on :p
John :)
Click to expand...

now thats funny :LOL: sods law strikes again.
 
No Tommy Cooper was funny, that was just unfortunate
 
Way back in the early 1990s I was advised by the MOT inspector (from what is now VOSA) to discontinue the practise of placing my hand over the exhaust to check for leaks. He told me that with the coming of catalytic converters and lambda sensors, blocking the exhaust could damage the lambda sensors. But to blow the cat completely is real bad luck!
 
That's something I have always thought could happen John but as it never has I still do it, whether your experience will change that remains to be seen :D

Peter
 
I can't think of any reason why it should damage a lambda sensor, and certainly not the cat brick. Most lambda sensors seem to have a "spark plug" thread on them and spark plugs seem to stay put in the face of huge pressures and temperatures - applied several thousand times per minute at full throttle! To physically blow the lambda sensor out of its hole, with the engine just idling, there must have been something seriously wrong with the way it was held in. Normally, a small engine like that will just stall after a while if you block the exhaust.
 
changed the blower motor on a mates merc 190 which involved removing all sorts from under the windecreen scuttle area, including the wiper.
When i removed the wiper the arm slipped out of my grip and smacked into the windsreen cracking it! :oops:
 
again s.ods law strikes again.bet at the time like john it makes you bloody angry but looking back it gives you a wry smile. ;)

i tied a marrigold glove to the exhaust of a transit i used to drive,bejesus they dont half get big before they explode.in hind sight should never have done it because it couldve caused damage to the van and anything else nearby,certainly made quite a few people come out from there houses sounded like a bomb going off.
 
Avocet said:
I can't think of any reason why it should damage a lambda sensor, and certainly not the cat brick. Most lambda sensors seem to have a "spark plug" thread on them and spark plugs seem to stay put in the face of huge pressures and temperatures - applied several thousand times per minute at full throttle! To physically blow the lambda sensor out of its hole, with the engine just idling, there must have been something seriously wrong with the way it was held in. Normally, a small engine like that will just stall after a while if you block the exhaust.
Click to expand...

I'm afraid I didn't explain that one too well......the lambda sensor screws into a threaded boss that's welded to the downpipe - the entire weld blew away!
No matter, that job is done - but before the event the management lamp was on, and the code indicated an exhaust issue. So, new cat, 2 new sensors and guess what....the lamp is still on even though I cleared the fault code :eek: The car is back with its owner now, and there's no change in performance so I'm out of that one!
Best wishes
John :)
 
Ah that makes more sense! Light might have been on because the lambda (at one or other sensor) was out of range - presumably because there was an air leak and it was getting a false reading. No idea why they should still be on afterwards though - unless there was a separate pre-existing fault or maybe one of the leads got damaged when it blew out and there's either a short or an open circuit?
 
gregers said:
again s.ods law strikes again.bet at the time like john it makes you bloody angry but looking back it gives you a wry smile. ;)

i tied a marrigold glove to the exhaust of a transit i used to drive,bejesus they dont half get big before they explode.in hind sight should never have done it because it couldve caused damage to the van and anything else nearby,certainly made quite a few people come out from there houses sounded like a bomb going off.
Click to expand...

Wouldn't have bothered the van! Just shows how far we've come on the 'elf 'n safety route though. When my dad was young, they were forever shoving spuds up car (and bike!) exhausts! (and they really DID make a bang)!
 
Avocet said:
Ah that makes more sense! Light might have been on because the lambda (at one or other sensor) was out of range - presumably because there was an air leak and it was getting a false reading. No idea why they should still be on afterwards though - unless there was a separate pre-existing fault or maybe one of the leads got damaged when it blew out and there's either a short or an open circuit?
Click to expand...

I'm genuinely at a loss about this one - the EML light has been on for at least a year, and the scan has always indicated the same lambda fault.
I've left things be, until such times as this one so now the exhaust is perfect for all I know. Certainly there are no leaks!
The new sensors were BERL specified for this car (I don't use universal ones) and they came complete with 4 wires and moulded plugs which fitted perfectly.
After doing the work, the scanner indicated the usual lambda fault which I cleared. The next scan showed up no faults, but the lamp remains on :eek: I just don't know!
John :)
 
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