Do I need to worry about contamination of cambelt?

pete_wood_uk · Unread post by **pete_wood_uk** » 05 Apr 2005, 14:46

Hi All
Took the engine covers off my HDi Xantia for the first time for a few weeks, and found that I've had a minor leak on the union carrying fuel into No.2 injector; the little cups in the head casting under the injectors were full of diesel. Impossible to say how long the problem has been present.
I was 200 miles from home, so I dropped into the local Pug main dealer who applied a large spanner to the union and nipped it up, so it's now dry again. However....
Looking at the shape of the casting, it's *possible* that under heavy left-hand cornering, diesel from those little cups in the casting could have run to the right and dripped down the hole between the head and the cambelt cover. The engine will have been spinning at the time, so any diesel hitting the pulleys will have been thrown off, however I suppose that the cambelt could have had a few drops on it. Can't say if this has happened or not, have no evidence one way or the other.
Do I need to worry? The cambelt was new only 6k miles ago, it would be a shame to have to do it again...
Thanks
Pete

oilyspanner · Unread post by **oilyspanner** » 05 Apr 2005, 14:56

I would spray a can of degreaser around under the covers then jetwash it off to remove any fuel that might contaminate the belt, just for peace of mind.
Stewart

fastandfurryous · Unread post by **fastandfurryous** » 05 Apr 2005, 17:22

I woudn't! Degreaser is just as likely to attack the belt as oil or diesel fuel! I would slowly rotate the engine, having a good look at the condition of the belt. Providing there is no obvious marks or stains on it, then it's more than likely to be fine.
Camshaft drivebelts have to deal with very small amounts of hydrocarbon contamination anyway, so the vague possibility of a tiny amount of diesel fuel possibly having been in contact with it for half-a-nanosecond is almost irrelevant.

pete_wood_uk · Unread post by **pete_wood_uk** » 05 Apr 2005, 18:51

Thanks. I suspect that, living where it is, with nearby oilseals on crank and cam, the cambelt must be designed to cope with some oil-based contamination.
Pete

pete_wood_uk · Unread post by **pete_wood_uk** » 25 May 2005, 19:11

Just thought I'd revive this thread to report back that the leak had clearly been significant. Before I found it (and got it fixed), the car was returning around 47mpg fairly consistently. Since the leak was fixed, it's now delivering around 51mpg. So a bit under 10% of all my fuel was going onto the road, and clearly had been for quite some time. Hey ho.
Damned plastic engine covers... I can't say that the car was much noisier with it off, so why do they fit them?
Pete

jeremy · Unread post by **jeremy** » 25 May 2005, 19:28

Apart from producing a tidy looking engine the covers help prevent you getting your clothing or yourself caught in the belt with unpleasant or even fatal consequences.
You wouldn't work with machinery with safety gaurds removed so why is your car any safer?
Jeremy

fastandfurryous · Unread post by **fastandfurryous** » 25 May 2005, 22:44

There is also the consideration that the guards do keep a lot of the road grime off the belt. I have run with the front cover missing for a little while before, but I wouldn't recommend it.

np · Unread post by np » 25 May 2005, 23:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by pete_wood_uk

Damned plastic engine covers... I can't say that the car was much noisier with it off, so why do they fit them?
Pete
<hr height="1" noshade id="quote"></blockquote id="quote">
Proberly to cut the noise down a bit,but more than likely to put people off from a bit of DIY.A lot of people are proberly put off by the engine cover so take it to the dealers to have work done.
Myself,i like to see an engine not hidden by loads of black covers.I expect Alfa are the only ones not to cover their engines up these days.Have you seen their V6`S?Thats how an engine should look[8D].

Unread post by **CitroJim** » 25 May 2005, 23:34

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jeremy

Apart from producing a tidy looking engine the covers help prevent you getting your clothing or yourself caught in the belt with unpleasant or even fatal consequences.
You wouldn't work with machinery with safety gaurds removed so why is your car any safer?
Jeremy
<hr height="1" noshade id="quote"></blockquote id="quote">
They also help to keep foreign objects (e.g. stones) out of the cambelt area which could get 'twixt belt and sprokets and either snap the belt or rip teeth off and either way cause engine severe damage...

citronut · Unread post by **citronut** » 26 May 2005, 00:11

i think pete was refering to plastic under tray not cam belt covers,in which case recon they are because of EEC rules and reg for nouis and oil spills regards malcolm

Unread post by **Peter.N.** » 26 May 2005, 00:39

The velocity with which the cam belt moves is enough to throw most contaminents off, so unless it's been lying in oil or looks worse for wear it is probably OK.

paranoid · Unread post by **paranoid** » 26 May 2005, 00:55

Work mate had this on his Picasso HDI when he first bought it, only came to his attention after I noticed the smell,He thought all diesels stunk of diesel!!! running the engine at high revs showed a fair ammount of diesel seeping out (but only at highish revs) He too had better fuel consumption after the unions were tightened. On checking the leakage it seems to drip and cling to the head rather than splash about
He was told that it was because a certain sustained speeds frequency of vibration was just right to undo unions slightly, also a sign that the vehicle has spent most of its time on the motorway