Renault 6TL "Crapaud"

[MikeKnight]

I've been trying to help but the weather has been awful and I've been ill (and vulg still sports a nasty cough) so every time we spend more than ten minutes outside in the cold it sounds like we're actually dying.

 

I cleaned the carb at my workshop as best I could but this solex piece of crap is almost impossible to clean thoroughly without a hydrosonic bath. I'm more used to dealing with Dellortos and Webers which are easy in comparison. I suspect one or more of the jetting tubes are blocked because of the stupid way it's constructed. I brought the mobile compressor back from the workshop so we can try blowing out all the tiny, tiny, fucking micron sized holes in it.

 

I'm also prepping an '06 Renault Scenic for sale which smells like someone died in it, bowel/bladder emptying and all.

 

I HATE FRENCH CARS.

[dollywobbler]

I had ignition silliness with the Dyane and 2CV. Drives you mad. Both ran in the end though and I managed not to destroy anything in anger! You'll get there.

[406V6]

Applaud your efforts in getting this old unloved car going. It's one thing to fix a working car that's just broken but you've got a much harder task - to get the car going from an unknown state where who-knows-who has mucked it up. You can't trust any bit of it to be working.

 

When you've got it running (and you're almost there) you'll feel so much better.

And everyone on here is willing you on even if we can't stand alongside and cheer in person.

[MikeKnight]

We put the compressor on the carb and I'm fairly sure it was blocked, as quite a bit of varnish-type crap oozed out before fresh fuel came out the same holes.

 

We're concentrating more on the Princess for a while as it's so close to MOT-able status.

[Cavcraft]

Keep the faith Olga Velour, you'll be over the moon when it's running.

[Timewaster]

Also bare in mind this may be the reason it was dumped in a field in the first place.

[Uncle Jimmy]

This is epic, actually dying whilst trying to fix a Renner 6; Mike Leigh will want the films rights to this thread.

[vulgalour]

Here is a little update on the little car.

 

The main problem identified is that I wasn't setting things up on the compression stroke.  I'd got so confused with all the information thrown at me I'd got muddled.  This is now resolved, it is now set up on the compression stroke.

 

The other problem is that the valve clearances had tightened up and were not letting the valves operate properly.  I haven't got my feeler gauges at home so I set them to as near as I could without.  I will reset these properly.

 

Sorting those two issues out in turn showed me that the distributor drive cog was in fact in 180 degrees out.  When I put it in with the engine out of the car I'd actually done it right so it had to go back to how it was.  I had definitely been overthinking this bit!  With that back in properly the rotor arm now points at #1 when it should.

 

Here is a little video demonstrating what it's doing.  The video is a bit crappy, apparently I used a potato instead of a camera.

 

You can see it's not quite right.  My understanding is that this is down to incorrect valve clearances.  Three of four bangs are going down the exhaust like they should, one is coming back through the carburettor, hence the little plume of flames.  I'm hoping when I set the valve clearances properly, all the bangs will go down the exhaust and the car will run.  That is what I'm going to try and I will see what happens.

 

One thing I did do was compare my brand new early R5 radiator with my old late R6 radiator properly.  I knew the new rad probably would fit as I'd seen videos of cars running with them fitted.  It's surprising how similar they are in size and should be able to be modified to fit without too much grief.

 

Both hoses line up exactly, the temperature sender looks to be the same (didn't have a big enough spanner/socket to find out exactly) and the only issue really is having the one long bolt sticking out the bottom that I need to chop off or drop in the bolt hole it lines up with.  To fix to the 6 I'll make some little clamp type brackets for the top and bolt it securely in that way.

 

 

It's not much, but it's progress at least.  When I've got tools and time next week I'll do a bit more, hopefully even get it running properly.

[Uncle Jimmy]

^^^ For a moment I thought you were installing an accordion in the R6 to appease the French bastard.

[MikeKnight]

I think the valves are just set wrong, but I didn't have a chance to look at it myself. Will probably take a look this weekend.

 

If I had to guess, it looks like the rocker is not letting the valves close all the way or the cam follower buckets are set high or something.

[320touring]

That's looking much closer, and the new rad looks Splendiferousness:)

[vulgalour]

Today I reset the valve clearances properly with my feeler gauges, which is a rotten job due to access, and did find it audibly improved the combustion and the regularity of it.  However, it still backfires through the carb when it should be firing down the exhaust on one of four (I don't know which one).  So while that was improved, it wasn't cured.

 

After speaking to Andy and Mike, and trying to get my head around how things work, a stuck valve seems the most likely candidate.  So, all the pushrods were removed which means I'll have to reset the valve clearances again (yay) on Mike's suggestion so we could see what the car did.  I'm unclear of the result of that, in all honesty, but Mike seemed to think it was as it should be so I'm back to square one.  It's possible that just doing that unstuck the valve but I don't know because before I could summon the patience to put it all back together it started raining so I downed tools.

 

I have decided today, for definite, without losing my temper, that this car is not a keeper.  I hope I can sort out this running issue and get it going and through an MoT, but right now if someone shoved  sensible amount of money at me and took it away, I wouldn't be sad to see it go.  I'd rather sell it after it's gone through an MoT and I've got to drive it around a bit, but I'm not at all eager to drive it now, I'd rather it became someone else's problem.  Don't all rush at once though, eh?

[barrett]

Why not just chuck £200 at a garage and get them to sort it out? I reckon it's easy to suffer a bit of 'shite blindness' when you've been fighting with a car for ages and can't get to the bottom of it, but some bloke who is literally paid to fix cars and has no emotional attachment to thisone will probably diagnose and fix it an a couple of hours and then it'll just be 'done' - put it in the garage for a month and save up a bit of cash and let somebody else deal with the ballache

[vulgalour]

TL:DR - I don't want to.  I'm at a point where I'm comfortable letting the car go.

 

Long version - giving it to a garage to sort would be ideal, unfortunately I have trust issues with garages after me experience trying to get the Rover sorted out.  I also don't have very deep pockets so while I'd be fine for a small bill of, say £100, if it ends up being a really big job I can't afford it.  I also don't trust that a garage would tell me if the cost was spiralling and that, in turn, has its own problems.  I don't know if this is normal for garages, but when I set a budget and request updates I expect that to be honoured and up here it seems the norm for the customer to have to do the chasing.  I've probably just had bad experiences.

 

This hasn't been an emotional decision, it's been a rational one.  I haven't lost my temper, or got upset with it, I've just decided that I'm at a point where I can comfortably walk away.  I've achieved far more than I ever thought I could, I've learned a lot about how mechanical things go together and come apart and gained a lot of confidence in my own abilities.  There just comes a point where you realise you don't want to go any further with a project and walking away is sensible.

 

As it stands I don't know if the problem is a minor adjustment one, or a more serious engine out job.  I've already decided that if the engine has to come out one more time for any reason the car will be sold.  Life's too short to be stressed out by old French cars.  This is my hobby, it's something I do for fun, and the Renault has been a chore for quite a few months now.  I can't make any progress and if I keep hold of it then I'll just undo all the hard work and money invested in it, which would be foolish.

 

So, it's time for it to go to someone else.  Maybe not this month, maybe not next, but certainly this year it will move on to pastures new whatever point I've got it to.

[Mr_Bo11ox]

Youre snatching defeat from the jaws of victory Vulg! Its barmy to get this far with it and then jack it in. Don't you want to know if the engine you have rebuilt, works properly? I have never dismantled and rebuilt a complete engine so if you get to a point where you've got it running and it runs OK, you have already got one up on me right there.

 

Have you got access to a compression tester? That will tell you with 100% certainty if you have a valve stuck open.

 

I reckon its still an ignition timing issue. Are you 100% happy that the camshaft is timed to the crankshaft correctly?

[vulgalour]

I'm not 100% happy I've done any of it right.  If I was 100% accurate then it would work, wouldn't it?

 

Seriously though, I'm as sure as I can be that it's timed correctly both on ignition and on the chain.  Since the chain is an engine out job to check, I shan't be checking it again because I am not taking this engine out again ever.  I can put the compression tester on it again to find out what it's doing exactly if we can get the thing to go in the plug holes, I seem to recall last time we had issues with access because of the distributor location.

 

I'm not snatching defeat from the jaws of victory, the car is moving on this year regardless.  I don't want to keep it anymore.

[Dick Longbridge]

Didn't SOC recently offer to pay a visit to get the old bugger running?

[vulgalour]

I've already spoken to Andy.

[Mr_Bo11ox]

I'm not 100% happy I've done any of it right.  If I was 100% accurate then it would work, wouldn't it?

 

Seriously though, I'm as sure as I can be that it's timed correctly both on ignition and on the chain.  Since the chain is an engine out job to check, I shan't be checking it again because I am not taking this engine out again ever.  I can put the compression tester on it again to find out what it's doing exactly if we can get the thing to go in the plug holes, I seem to recall last time we had issues with access because of the distributor location.

 

I'm not snatching defeat from the jaws of victory, the car is moving on this year regardless.  I don't want to keep it anymore.

 

Now then! I imagine you're 100% sure that you refitted all four pistons for example.

 

I don't know what the timing mark situation is on these, i dont know how easy it is to get it wrong. I know that its very easy to get something wrong on the ignition timing side however. Anyway fair enough, your car, your call etc.

[Pillock]

Normally I'd suggest a gang of Shiters descending on your gaff and tinkering, but it seems with MikeKnight plus your perseverance that wouldn't help, you've got expert help already.

I guess once you've decided it's not a keeper, that's it, but you've come SO FAR with this and I've really enjoyed reading about your journey with it. I don't want to bully you into keeping it, but I reckon that idea with the photo of Piers Morgan and the scissors is a good one.... release the tension and get back on it.

[vulgalour]

Okay, so Mike picked up on this and suggested the following:  refit each push rod individually and set valve clearance.  Crank engine and see where the bangs go.  This should identify which valve isn't doing its job, if any.

 

Thing is, if all the valves check out, and the timing is to the best of my ability correct and it's STILL doing this crazy backfire thing then what could it be that's amiss?  I've gone over all the things so many times and gone back to the start etc. that I can't see how it could be timing at this point.  I genuinely can't understand how it's not running because I've done everything as correct as I can.

 

One positive thing though is that the carb does now work properly and squirts fuel like it should since it was cleaned out, so that's something.  Right now, however, I just have a very large crow scarer when any attempt to start it is made.

 

Oh, and there's no stressing being done here.  I'm perfectly okay with the fact it's not working.  Well.. not perfectly okay, but at least tolerant of the fact it's being French at me.

[PhilA]

 

 

Play this to it. It should begin working.

[Mr_Bo11ox]

If none of the valves are sticking open, then a backfire has to be a timing issue. That could be timing of the spark, or it could be that the camshaft is timed wrong to the crank (so the valves are out of sync to the crank), or both.

 

Can you be sure about the following?:

 

1) you can identify the point when cylinder 1 is at the top of its stroke and both cyl 1 valves are closed. (Stick something through the spark plug hole if necessary to check the piston position).

2) when those two conditions are met, is the rotor arm defo pointing at the quadrant of the dizzy cap which has the no 1 plug lead going to it?

[vulgalour]

I am as sure as I can be that those two points are correctly set.  There is no point in my looking again, I've checked it so many times now that if it's wrong, then I'm seeing it wrong and so is Mike.  We even went to the extent that Mike went through the ignition timing without me pointing anything out or helping and he found nothing amiss so I have to believe it's correct.

 

Therefore, the strongest and currently only theory is that of a sticking valve.  This is why Mike has offered to go through it the way he has.  Mike did ask me if the valve stems were bent earlier today and I pulled a face, because even I'm not stupid enough to put a bent valve in a newly rebuilt engine and I don't have x-ray vision to find out if it's bent since the rebuild.  So at the moment, Mike, yourself and Scary are all suggesting it's a valve issue and I am going along with that because I don't know any better at this stage.

 

Whatever the problem is, it's going to be something daft.  It's also entirely likely that just undoing stuff today and putting it back together could have freed something off that was causing the problem so it might magically work tomorrow and we'll never know what was wrong.

[DodgeRover]

Are these an interference engine? I wonder if when it was spun over with the cam timing a piston kissed a valve or 2 causing them to either not seat or stick a little?

[vulgalour]

This is the final update on this project.  I have reached the point where I have done all I can and all I am willing to do and it is now time to definitely move it on.  I no longer wish to spend any more money or time on this car, it needs to become someone else's problem.

 

Today I went through and one at a time installed the pushrods and set the valve clearances to find out which valve was causing the backfire through the carburettor.  Mike was helping me understand what should happen and what should do what.  Eventually, it was identified as being inlet 1 and 3.  The car would turn over without backfiring if those two pushrods were removed.  To demonstrate, I took a short video at which point the car promptly backfired through the carb, like so:

 

 

I'm sure for someone this is a quick and easy fix.  For me it's the point at which I stop.  I am not interested in taking a gamble that it's a quick fix or sending it to a garage.  I no longer enjoy this project and if I keep hold of it, I will not make any progress.  It's time for it to go.

 

This is a rational decision, not an emotional one.  I will no longer be making any attempts to sort this out.

 

Sometimes with a project you have to decide when to walk away.  This is that point for me.  If you are interested in purchasing the car and all the spares then I'd like £600 or thereabouts for it.

 

Apologies to those that will be disappointed by this being the end of my adventure with this car, I know you've been cheering me on and hoping I'd get there.  Someone out there will know how to put this right and will want it, that someone isn't me.  I'll be making a formal for sale advert later.

[adw1977]

I've been following this thread with interest for ages, not contributing because frankly I know nothing remotely useful, but hoping that you would get the car going.

 

Although you weren't able to finish getting it back on the road, the work you have done has ensured that it will get there before too much longer. Considering you bought it for scrap money when it had been off the road for two decades, I'd say that's an achievement and you have definitely saved this little car.

[MikeKnight]

If I had to take an educated guess, I'm guessing the cam is lined up incorrectly as the valves are not closing properly when they should. Regardless of distributor ignition timing. We've played about with the valves clearances and they all do seem correct.

 

We did give the head to a workshop I know and trust who've rebuilt engines for me in the past (and are indeed part of the federation of engine rebuilders/remanufacturers) and on closer inspection I can see they've done some things wrong. On this particular engine all the valves springs go on one way only and the closer spring coils need to be against the head and not the end of the stem where the more open coils need to be. A few appear to be upside down. But some of the valves that are seemingly stuck open have their coils the correct way around so I doubt this is the actual problem.

 

But the cam (chain) timing is set up exactly how the book says it should be, and indeed all the people vulg has asked have agreed it's correct. I looked at it, the engine workshop looked at it, we all nodded in agreement that it's correct.

 

So I'm fucked if I know what the hell is going on.

 

The ONLY thing I can guess is if the sprocket on the end of the camshaft could possibly be fitted in more than one position, and it's currently fitted in the wrong position. But that's grasping at straws and would still require taking the engine out.

[cobblers]

Is it just my eyes or is the third valve from the left in that video not opening? 

 

Ignore me, pushrods removed.

[vulgalour]

It's not your eyes, there's no pushrod in there to open and close it.  The video shows the engine running with two pushrods removed as they were identified as the ones causing the backfire through the carb.  After they were isolated, it then didn't backfire at all until I recorded the video at which point it decided another one of the valves was going to cause a backfire.  The problem just decided to move to another valve somehow.

 

This is the thing that's so frustrating about it.  You identify where a problem is, isolate or rectify it and then the problem moves somewhere else.  To resolve I'm pretty certain it needs the engine draining, removing and rebuilding from scratch again by someone that knows their way around an engine well enough that they don't need the manual.  That person is not me.