Renault 1.9 diesel head rebuild

Get a replacement head from a scrappie assuming you can find one. It'll be cheaper and less aggro than reconditioning the disaster you currently have I suspect!

Well I rebuilt the old head - once I'd stripped it down the damage wasn't too bad, possibly because it was only idling when the belt snapped. Two new valves (not that they even looked bent) and a new follower, plus the usual gaskets, bolts, valve guide seals, etc.

It's all back together again now, but running like a pig. Very little power, lurching and kangarooing all over the place every time I press or release the accelerator. Doesn't idle very well (idle speed oscillates up and down). It did smooth out a bit over the 2-mile test run I did tonight, but I wouldn't fancy driving it in heavy traffic.

At first I thought I still had air in the injector pipes, but it never took this long to flush out last time I replaced the fuel filter. I'm not that familiar with diesels' foibles, if it was a petrol I'd say 'fuel starvation'.

Stuff I've already done /checked:

- Ground-in all the valves, then checked for leakage with a few mls of petrol down the ports

- All valve clearances within spec

- Valve motion nice and smooth, no sticking

- New head gasket & bolts, head & block faces cleaned & checked with straight edge

- Cam & pump timing agrees with marks on sprockets, cover, belt & flywheel

It was starting to hunt and lurch, expecially on the overrun, a while before the belt went. Also at a steady motorway speed, giving it more gas would make it go slower - ease up on the pedal and it'd accelerate again. There was never any black smoke though.

Based on all this I think it's something in the injector pump / governor (it seems like it's not being damped properly), but having very little clue about how these work internally I'm out of ideas. It's a Lucas-CAV pump.

Any hints what to try next would be much appreciated.

Cheers

Rhydian

I think I'd check for an air leak letting air into the fuel pipe ..... filter connections perhaps, try putting a clear length of pipe into the fuel return pipe . Bubblesin the return? If so then try further back along the fuel feed , before the filter and after it. steve the grease

Check the timing again, preferably directly & recheck the belt tension, Odds are that's the fault. It's not unknown for the factory to fit the pump one tooth out on the belt & then time it up.

"Rhydian" wrote in message news:438659c3$0$9472$ snipped-for-privacy@ptn-nntp-reader02.plus.net...

Snip

Hi Rhydian,

Sorry to hear about the 1.9, you?ve certainly gone to a lot of effort, I owned a renault 1.9 diesel, non turbo, k reg Clio a few years ago. I also did, and had a lot of work done to this car, about £2500 worth in the first two years of ownership? I would never own a renault again. But this doesn?t help you, so; my Clio also had a CAV fuel injector pump that caused a number of problems, due to air getting past a plastic bush around the throttle lever shaft. Took it to Renault and they said "that I would need a replacement pump fitted"! Their price was about £1200 + VAT! So I spoke to a local, London, Taxi firm and they referred me to, I think ?Tower Diesels?, near tower bridge. They were brilliant and just replaced the CAV top panel, cost £150, and what a difference that made to the engine?s performance. Also the plastic bleed valve at the bottom of the fuel filter leaked, onto the ?pre heat? box! Due to it?s washer de-grading, I cut my own and it worked a treat, better than the original. If the belt has broken, then, with this engine, contact has been made between the valve and the pistons, you?ll be very, very lucky if you don?t need a re-conditioned complete head. Remember that nearly all the torque is available at very low revs, with a diesel, delivered to an aluminium head, I think it?s the cam shaft mounting points that get disturbed, even 1thou or 2 would cause a problem :~( I now own, for my sins a Seat Leon 1.4, (Spanish VW) and I?m still as cynical about cars as ever, but above the cost of the usual servicing, in three years it?s cost me £000. I know, you wait for the forth year ;~) All the best in your effort, Michael.

All the above was done at night, with a torch and a floodlight - I saw it running in daylight for the first time at the weekend. Clouds of unburnt fuel coming out the exhaust, it's only running on 3 cylinders. It eventually struggled up to 55mph on the flat on a longer test run. I can't check the compression as my tester only goes up to 250psi, but it looks like valves and/or gasket aren't sealing properly. In hindsight I should have got a longer bar to do the angle-tightening on the head bolts as it was a real struggle for a 10 stone weakling. That and get some better head bolts next time, the ones I got had those horrible inverse-torx heads which seemed to be made of plasticine.

Anyway, thanks for all the replies but I've had enough, it's off to the scrappy unless anyone on here wants it for spares or repair.

Moral of the story : Never, ever believe anything the seller tells you unless there are bills etc to back it up! ("Oh yeah, did the belt myself just last month") The stupid thing is I wouldn't have minded changing the belt if he'd told me, it would have been less of a PITA than all this. Oh well, you live and learn...