16V (nice and tidy valves) no more troubles

[mechuccio]

Hi dr. Nick

Hi everybody!

Yesterday I've purchased a MK1 16V with some troubles:
This car has been property of the previous owner for four years.
Around 40K KM's he changed the distributionbelt, together with the two tensioners and the waterpump.

About a month ago his girlfriend was driving it and had to make a sudden stop, apparently she braked hard without using the clutch so the engine stopped running and hasn't ran since....
They tried to start the engine a couple of times after that, the engine turned as it should (no weird noises) but wouldn't start.
He checked the distribution belt and found out that it was too loose and could remove it by hand without too much effort, and as such expected that the timing went wrong and he didn't want to invest in this car anymore.

So yesterday I picked it up by ambulance and today I started working on it.

Because the timingbelt was already removed I needed to set the sprockets right in order to block them with the designated materials (e.g. a drill and 2 inbuswrenches carefully carved into the right demensions since I allready have a 16V) I had to turn the camsprockets about a third of a stroke, and the driveshaftsprocket about twice that. All this went without strange tensions in the engine and felt as it should (I've got a spare cilinderhead in my attick and fiddled with that for a bit and the cams feels pretty good, the same as my spare head as for the tensions provided by the valve-springs.

So I placed a new timingbelt, turned the engine a couple of times by hand to make sure there were no pistons touching the valves, and all went well, exept for the fact that I misplaced the belt so the camsprockets where off by one tooth of the belt. Reinstalled the belt again and now after a couple of turns the blockingholes where perfectly aligned.

I then tried to start the engine, it turnes nicely but it won't start.

Ofcourse I do have to check the compression, but I won't be able to check that until monday nor will I be able to do anything on the car for that matter until monday.

But I do have a couple of questions about this phenomenon:

When the timingbelt would have failed, and the pistons collided with the valves, and some of them would have been bended. Would it still be possible to turn the engine by hand without any restrictions or noises? I know the XU9J4 has pistons with spaces in them for the valves otherwise under normal conditions they would hit eachother.
So my theorie is that when I'm able to turn the engine with the timingbelt in place let alone with the cams off, the valves would be in order, right?
This because I have a cilinderhead as well with 6 bended valves, on this head the valves keep sticking out because they're bent and won't fit in the head anymore.

If anywone could confirm that?

Then, while starting, and I did that for a couple of times and several times well more then a couple of seconds with and withoud full throttle. I can't sence the least bit of fuel fumes. I would suspect that it would smell badly of unburned fuel wilst drowning my engine.

I've tested all the plugcables, every cilinder has a spark. Also I detached the fuel hose that's connected to the fuelrail and there is fuelpressure.

So my guess (and mainly hope) is that the fact that the engine stopped turning is not due to a malfunctioning timingbelt but due to something else..... but what? is there anything that could have happened while stamping on the break paddle without using the clutch that could be responsible for this? I'm suspecting that the injectors don't open, but I've cleaned the connectors (to the point where the cables go into the carrosserie) but that didn't help a bit. I should as well measure the signal that's being sent to the injectors (if any) but again, not untill monday.

I hope that someone here has some answers to my questions. I've bought this car for 300 euro's and it has ran just 220K KM's which is well under my MK2 (but my MK2 is my sweetheart, that'll never go!) I'm hoping to fix this black MK1 for a friend of mine.

Well...... thanks!!

[Simran]

Sudden braking would cause the engine to jolt on its mounts a bit so maybe some cables were pulled loose or broken, but then the engines movement shouldnt have been enough to cause anything to unplug i wouldnt have thought. Maybe some connection was already loose which was just worsened by the sudden braking?

[mechuccio]

Thanks!!

And yes I also suspect that the problem lies somewhere in that area.
Also there is an old alarm installed, which according to the previous owner has been shut off. But there could be a startblockingsystem active all of the sudden (Can't smell any fumes of unburned fuel)

I'm goint to have to do some measuring I guess.

But do you know if my theorie is right as for the pistons hitting the valves when 1 or more has been bent? When I take a look at my rubbished cilinder head I can see clearly that the valves don't fit anymore, an besides that they're off as well so won't fit in the spacing in the pistons. (that cilinder head comes off a 16V of which the timingbelt broke while ideling)

[thanuttiscotsman]

hey man make sure the injector relay is working! or maybe the injectors aren't actually squirting! you should hear a click i think when you turn the ign on, in fact the easyest way to tell is to take a spark plug out of the head and try starting it, if the injectors are working then you should see puff's or mist spray of fuel comiong out the plug hole when turning it over.
also take the fuel pipe off at the regulator end of the rail not the inlet end! as you need to see the pressure regulator is functioning.

cheers rossco

[ollie]

In response to Q on valves, most engines which have jumped a few teeth and bent valves turn quite happily! theyv'e made all the clearance they need !! some even feel "normal cos not all valves will neccesarily be bent, just slightly enough to prevent them fully shuting.

However a car stopping on the brakes is hardly excessive deccelaration by engine stamdards so isn't particularly likely to jump teeth, some 16v are fairly slack anyway with no apparant reason, which is why I try to check them at service times. I suggest you do the elsewhere checks like the previous owner should have done before dismantling! - an unplugged sensor or rattled relay would be much more likely.

Ollie

[mechuccio]

Thanks for the responses!

It gives me hope I've bought this valver with not too much troubles for not too much money

I do hear the click when I turn the key, but I don't here the buzzing sound that I do have on my PH2 (but that one runs on autogas, so that could be responsible for the buzz, I don't know, haven't had too much valvers yet.

And I did take the fuelhose off the inletside of the rail, so I'll check the outlet as wel monday.

And yes, I'm going to check all that can be checked, I didn't know that the engine could be turned with bent valves so a compression test is still in order. Further ofcourse all the electra has to be checked.

So the plan is to firstly remove the alarm, then check the compression, and if all that is in order try to start it again. If it doesn't run I'll try to measure as much of the electra as possible and if that doesn't give me an answer I'll just start exchanging sensors with my tidy up and running valver (allthough my red valver is a PH2 and the black(broken) one is PH1 both cars have the 160HP XU9J4) so I'd suspect they are the same. haven't compared the ECU's though.

Well, I'll keep you posted if anything new happens!

[Simran]

Sounds like its definatley electrical if you cant smell fuel but you seem to have fuel pressure. Alarm systems normally cut one or two circuits when they immobilise, usually the starter solenoid circuit and something like the ignition, injection or power to the ECU. Injection would be the most sensible as cutting the ignition would mean fuel being sprayed in and not being burnt which isnt good in many ways.

[Timmo]

when my belt went on mine before i took it all apart (like you had a spare complete head in the loft) i put on a new belt, timed it up and turned it over as per the book etc. did turn very easily, although wouldnt fire up, (didnt expect it to but you never know!!) on removal of the head found 10 bent valves! so it could quite possibly be that there are a few bent valves on the head thus why its not firing!!
mt belt went when accelerating from a 30mph limit up to approx 50 (in 5th),

one thing i did find though is that htey do like a good distributer cap and rotor arm to give a good spark!

its not all that uncommon for a valver to jump a tooth on an old belt when being bump started, so quite possible that a very hard effort on brakeing could have caused a jump if thebelt was loose!

[mechuccio]

And thats what I'm not hoping for offcourse
But it is then possible to turn this engine with bent valves.
A question though, did your belt break? or just shifted a couple of teeth?
According to the previous owner the belt seemed fine when he took it off (too bad he threw it away )

I could not find any marks of a broken belt on the engine or the distribution cover, I'd suspect it would have left some marks somewhere right?

And when you were starting your engine, could you smell anything like unburned fuel maybe?

Oh well, I'm just going to have to do the compression test, that'll tell me exactly whats up with this engine.

Still hoping the problem lies in the electric range though (offcourse )

[thanuttiscotsman]

hey man, i think you should check the injectors are firing first, if bent valves were the problem i dont think they would all be bent so the car would still fire on some cylinders but it isnt, though i have seen petrol cars with fecked engines with little or no compression still running so i dont think thats your problem. i think there would be audible or some other signs of damage. the easiest and fastest way to test the injectors is to remove a plug and turn it over, if they work a mist of fuel will puff out the hole if no mist then no fuel so it would probally then be fuel injector failure or fuel pressure related if not then lastly an ign problem. i have had 16v's with starting problems before and when testing it i removed a spark plug and earthed it on top of the engine and it did spark but only a dull yellow spark, i then assumed the ign amp was ok because i seen a spark but later to find out it was the problem alla along it was too weak to start the car i put a new ign amp in tested it to find a bright blue spark now and it started first time! anyways have a go and let us know how ya get on.

cheers rossco

[Timmo]

yeah was very easy to turn the engone over witn the bent valves,

tbh, your bound to be able to smell fuel as the engines all working how it should except its not firing! the fuel isnt being burnt off and sent off down the exhaust system etc!

your best bet will be a compression test!

yes my belt failed in a wonderfull manor! hahah! afaik rossco it wont fire up as it needs the compression to work, if the valves arnt sealing its not getting the compression, if they were all sealing as they are meant to then it will fire up on 3 cylinders and run just be down on performance!

if it did jump a couple of teeth i'd be willing to bet its bent a valve or two!
if youve got a spare head all ready then its not a difficult job to do! prolly take you a morning/afternoon to do!

[mechuccio]

Thanks again

Well I will have to remove the sparkplugs monday in order to perform the compressiontest so I'll check for a fuelmist then.

And indeed I'd suspect if the belt jumped a couple of tooth that some valves were bent (surely don't hope so) according to the previous owners story there wasn't any ratteling noise when it stopped. It just didn't want to start anymore all of the sudden. But it could be well possible that some valves are bent. If so I'm just going to take the good valves from my rubbished head and put them in this head, I guess it shouldn't take me more than one day to do so, and in cost effect It would just cost me a new gasket and a set of stretching bolts (together 80 euro's) Still not too much for a valver

And I'll surely keep you posted!!

[Timmo]

mine went quietly too! no nasty noises at all!!! hence why i tried a replacement belt on it prior to removing the head!!!

you'll need a long reach valve spring compresser for the job (remember being informed so from trusted members when i mused about doing my spare head!) but yeah, shouldnt take you overly long!
and like you said, will be nicely cost effective when your done!

[ollie]

lots of the trade try belt first in the hope that it won't have bent anything, but in reality this is a waste of time with most engines - it either has clearance so they never touch, or it doesn't!!

some Pintos, MX5 and a fair few older vauxhalls don't crash valves, but its beter safe than sorry for anything your not certain of

Often just buy a scrap engine myself cos it can work out cheaper than the valves alone on some, plus you get a fresh head and cams which haven't seen any impact or dents in the followers.........
some engines weaken pistons too which drop apart a few days after reassembly

XUD's are good for bugering cams at the same time - allthough with some setups its the cam which breaks first before the belt- gets fatigued by knackered pumps on the end with muppets holding their car on full lock pulsing the PAS

Ollie

[mechuccio]

Thanks for the replays

Today I couldn't do too much on the valver, first I had to drive to Belgium to pick up a shitload of C35&C25 mechanics, and that was a lot, really a LOT!

All together that was a 500KM trip and after that we wanted to start on the valver, but at the first attempt to unscrew a sparkplug my sparkplugwrench broke in several little pieces and as such we spent the rest of the afternoon picking out the pieces of my wrench.

There was one thing though that I'm certain of, there was a live mouse running around under the bonnet, so it doesn't have a cat!
Lets hope that the little critter didn't damage any of the cables.

But I bought a new wrench for the plugs, so tomorrow we'll give it a new attempt to measure the compression.

(we did one way of testing though, when I unplug my bobine and hold my hand against my exhaust it kinda feels the same as the MK1 when starting (air being pushed out)