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Discussion Starter · #1 ·
With all the recent talk of worn cams on the V6.......I started thinking about my puny 1.8litre 8v :(

I still have a slightly lumpy tickover when warm. I have tried 3 different temp sensors (1 brand new) and all exhibit the same slight lumpiness when the engine is at 80ºC and above, so I don't think it's that at fault.

Again I've tried 3 different lambdas and the exactly the same happens so I think I can rule that out too.

I use Shell fuel and not supermarket stuff.

Could worn cams cause this ???
I have a good set in the shed I could use, but don't want to have the hassle or expense if this is not likely to be the cause.

The engine also sounds a bit thrashy above about 5800rpm. I've tensioned the chain but this hasn't helped.

Any suggestions guys ????:(
 

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Marlon,
If worn cams are suspect, would a wet/dry compression test tell you?
 
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Discussion Starter · #4 ·
It does.........

Can you see one of the cam lobes if you remove the oil fillet cap? You may have a ridge at the edge of the lobes indicating wear.

wrinx
 
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Discussion Starter · #5 ·
I can't, only see the chain and end of the cam, but I should really take the cover off to see shouldn't I ???

Maybe a job for the weekend (it'll only take 15 mins to get off :rolleyes: ).
The top end was rebuilt about 45000 miles ago, so it may be a bit worn again I suppose, especially the way I treat the poor thing :eek:
 
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Discussion Starter · #6 ·
Bugger :( On the 16v's you can see the end of one to give a bit of an idea about wear.......off with its head then :D

Trying to keep up with all these beastly V6's does take it toll on the little fish ;)

wrinx
 
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Discussion Starter · #7 ·
hi,i ran a 75 for a few years which had a habit of chewing exhaust cams.on number 1 cylinder the lobe was just about gone and the bucket had been worn badly but it ticked over great you should notice a top end rattle like a 16v with a duff variator
 
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Discussion Starter · #8 ·
if there worn its a good excuse to throw them away and buy a .moster set of cams :) ones that nearly catch on the cam cover and shapped like house bricks :lol: :lol: it would give a few v6s a shock :eek: :lol:
 
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Discussion Starter · #9 ·
wrinx said:
Trying to keep up with all these beastly V6's does take it toll on the little fish ;)

wrinx
LOL, tell me about it :rolleyes:
Once moving my car is rarely below 4000rpm. It's now on 112000 miles. It's had a hard life. I couldn't believe how much of a thrashing the last owner was giving it while telling me tails of how fast he could get the thing to go on certain stretches of road.

Can't afford to upgrade to a newer model just now.
The lumpiness isn't bad, but I notice it and you know how you get a bit worried when you realise that something is amiss with the 155 :eek:
 

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When the exhaust cam rattles like an old Simca it will be time to change the cam and followers. :) Funny how even when very worn they don't impair performance the way a worn inlet cam would. If anything, I would imagine idle and low speed torque would be IMPROVED with a worn exhaust cam. :)
 

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Marlon

the lumpyness might be caused by that chip you`ve got in and also your air filter arrangement :confused: and maybe the fact that its been tuned on the rollers to around 140bhp.................which will affect it and it won`t run the same as it did in standard form ;) ;) due to the different settings etc
 
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Discussion Starter · #12 ·
The lumpiness is there with the standard chip too :(
The car wasn't tuned on the rollers, it was just a see what I got run.

Hmmmmmm.....it didn't do it today at all. So might have to look elsewhere for the problem :(
 
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Discussion Starter · #13 ·
i would have a close look at the cam timing, you still need to remove the rocker box to check it anyway,you should see some little marks on the cam that line up marks on the cam caps(No3 cyl if i remember right)
 

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The other thing to check is that the variator is having power to it switched on and off. A duff relay or something else would provide a really lumpy idle- very pulsing.
 
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Discussion Starter · #16 ·
I'll check that but I'm sure the variator doesn't affect the 8V at idle (unlike the 16v).

As an update, the fault is intermittent, but again only when the engine is up to temp, so I'm assuming it electrical.
 

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It could just be a small leak in the valves owning to the fact the engine has been used enthusiastically. If it is, it will likely develop very slowly. I'm not sure if this could happen intermittently though, and if so to what extent. If the engine was allowed to warm up at idle, and the cat didn't get hot, it may be possible to see if there was a lot of hydrocarbons in the exhaust to support this theory. You would have to have it emissions tested without driving it though.
 
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Discussion Starter · #18 ·
Think I've sorted it guys (fingers crossed).

It looks like it was the AFM. In a last attempt to find the cause I took the AFM apart and cleaned the electrical contacts in the slider. I also found the screw which holds the moving bit was loose and so the fuel mixture settings were all wrong. This goes along with Mr T telling me the car was running lean at high revs.

Tightened it all up and set the basic fuel mixture with the cogged wheel. Ticks over nicely so far :)
Have to wait and see what the fuel consumption is like, but I don't get any popping on over-run anymore.
 
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