lumpy running scenic

vickyp81

scenic 03 mk1, 1.4 16 v petrol
71,000 ish miles

wen was going down duel track car started losing power and vibrating/jerking/lumpy tick over

called rac they said was cat gone

cat been changed
coils changes
spark plugs changed
crank sensor changed

car still running lumpy any ideas please?
thanks

captainawsome

Sounds like some top class shotgun diagnosis to me. Compression test and cylinder leakage test next.

colino

No check for vacuum leak or MAF. That sounds like an excellent RAC patrol. Did he have the spare bits in his van?

forgotmyname

Who changed all those parts without a proper diagnostic?

Get it to someone else to diagnose it properly.

vickyp81

forgotmyname wrote: »

Who changed all those parts without a proper diagnostic?

Get it to someone else to diagnose it properly.

my bf changed the parts as was stuff he could think of wat it could be, and really cant afford to pay labour at a garage,


diagnostics has been done on it a computer says alls fine what is the head scrathing bit

forgotmyname

Computers cannot diagnose mechanical problems reliably.

Cannot afford to get it diagnosed but what did it cost to replace all those parts? And its still not fixed.

My sister ignored a fault on her car. Scrapped 3 pairs of tyres at almost £70 a piece for the sake of one part that cost under £15.

Engine light on? Tested the HT leads? Compression test, Lamba sensors tested?

vickyp81

forgotmyname wrote: »

Computers cannot diagnose mechanical problems reliably.

Cannot afford to get it diagnosed but what did it cost to replace all those parts? And its still not fixed.

My sister ignored a fault on her car. Scrapped 3 pairs of tyres at almost £70 a piece for the sake of one part that cost under £15.

Engine light on? Tested the HT leads? Compression test, Lamba sensors tested?

im not ignoring the faults, the car has not been driven since it started to run lumpy, no lights on dash, no faults found when plug it in, and cat had gone when emissions was tested so that needed doing before next mot, and so far only spent £90 on ALL parts changed and no labour what is the pricey bit.


all im asking for is some ideas where/what to check next. if I have to take to garage I will do but seens my bf can do a lot of work him self id rather not pay labour and just but parts

forgotmyname

But the CAT may have been OK. You failed to test the Lambda sensors which could be the cause or the poor running and poor emissions.

At the prices you mentioned i assume they are used parts. Do you know if those parts are actually in better condition that the ones they are replacing?

I didnt say you were ignoring faults. Working blindly maybe..

Next, HT leads, Lambda sensors, Compression test..

My sister has a megane with the same engine and all 4 coils have failed one after the other. Waiting for another call to say the 1st one we replaced has gone again.

colino

Vacuum leaks and MAF failure don't give direct fault codes, they need diagnosed (not code read) to understand, find and repair. Please stop throwing replacement bits at the car, it has probably cost you more than a proper repair already.

vickyp81

forgotmyname wrote: »

But the CAT may have been OK. You failed to test the Lambda sensors which could be the cause or the poor running and poor emissions.

At the prices you mentioned i assume they are used parts. Do you know if those parts are actually in better condition that the ones they are replacing?

I didnt say you were ignoring faults. Working blindly maybe..

Next, HT leads, Lambda sensors, Compression test..

My sister has a megane with the same engine and all 4 coils have failed one after the other. Waiting for another call to say the 1st one we replaced has gone again.

all parts are brand new, shopped around, it doesn't have ht leads has pencil coils( coil on plug)


my bf happy to replace those bits he has as its stuff what will go in time and was all original parts


he will look into lambda sensor and compression test

forgotmyname

Ignore me on the HT leads. I know the coils sit on the plugs i changed all my sisters (one at a time) Only seemed to be weeks before the next one failed.

£90 for a CAT and 4 new coils though. Way too cheap. Decent coils are £20 each.

So £10 for a CAT? I would expect a decent CAT to cost more than £80.

Your happy for him to replace those bits??? OH dear.. But replacing parts randomly will cost more than buying a new car.

He needs to diagnose the problem and test the parts before changing anything...