Technical Head gasket blown, balancing options, little money

[koalar]

You buy the belt and tensioner as a kit normally

Order the right on one, there's at least two different widths, two different profiles and two different adjusters

I never changed the water pump, had two pandas do 200k on the original no weeping

I have had several core plugs fail though on engines run on water only

You pays your money and takes your chance, I can change just the belt in 1/2H or so it's no big deal if it did ever let go.

 

[Pugglt Auld Jock]

Possibly, I don't know I'm going back a long time when I was an apprentice at a well known Jaguar dealership in Manchester. Bluecol AA and the like were the stuff used in those days. I think the general practice then was to use antifreeze in the winter then drain it out in the spring and just use water. I think I might have done that myself then. I can remember removing XK heads to find the water ports corroded away, as I alluded to in an earlier post.
Going back to the brake fluid in the water bit, it will mix as we all know, as this is why we should change the brake fluid in the braking system every couple of years due to water contamination.

I remember you used to be able to buy "stand alone" corrosion inhibitor for use if you weren't putting antifreeze in.

 

[jrkitching]

I remember you used to be able to buy "stand alone" corrosion inhibitor for use if you weren't putting antifreeze in.

You still can!

And this improves cooling system performance when used with plain water, since water has a higher specific heat than a 50% glycol/water mix.

You don't need a huge volume; I run my central heating system with a shade under 1% corrosion inhibitor.

Needless to say it's not a great idea to do this if there's any chance of the coolant freezing! I've seen engine blocks cracked this way, though if you're lucky, you'll just pop a core plug or two.

Some folks will add this as an alternative to changing the coolant.. It doesn't work out any cheaper if you;re doing the job yourself, but it's an option for the less DIY minded motorist who wants to avoid the labour cost of a coolant change. Not something I'd do, but it's better than not changing the coolant at all.

 

[PuntoHowTo]

See this video, 16v engine but the block and the principles are largely the same

 

[DaveMcT]

Clean out all bolt holes into the block. I use cotton buds (lots of) to soak up any oil/coolant that’s got into the holes. Do the same with any upward facing bolt holes in the head just to be sure.

Use brake cleaner on cylinder head and block surfaces. DO NOT clean the gasket other than picking off fluff from the packaging.

 

[DaveMcT]

When filling with coolant, get the concentrated stuff. Pour the correct percentage into the system and top up with water. I use water from dehumidifier as it’s effectively distilled. This way you’ll not over dilute the coolant.

Apart from the corrosion issues, coolant is important because it “wets” the metal surfaces better than water alone. Better thermal conductivity where it needs to be.

 

[koalar]

There's over a litre of that nasty coolant left around the cylinder jackets and in the matrix, I would put the bare minimum concentration in and run it for a bit, and see if it leaks from anywhere and if its maintaining it's level before dropping and refilling properly

The cause of the failure is still to be determined

They rarely fail on there own

 

[Keepthe12alive]

This is really, really helpful — thank you so much

 

[Keepthe12alive]

This is the latest progress — all belts back on

Only it seems like at worst the timing may be off by a tooth perhaps on account of the skim

How terrible is that?

 

[koalar]

The maximum skim is .004" or less than the average piece of paper, makes no difference to timing

The variator has to come off to be skimmed

There is no keyway

You will need all three timing tool to set the timing properly, unless you are extremely lucky

Cam lock
Crank lock
Variator lock


I have set the cam one tooth advanced, as an experiment and turned over by hand, nothing hits, the engine runs but does not rev properly


I can't say if every compilation of timing is safe

 

[Keepthe12alive]

The maximum skim is .004" or less than the average piece of paper, makes no difference to timing

The variator has to come off to be skimmed

There is no keyway

You will need all three timing tool to set the timing properly, unless you are extremely lucky

Cam lock
Crank lock
Variator lock


I have set the cam one tooth advanced, as an experiment and turned over by hand, nothing hits, the engine runs but does not rev properly


I can't say if every compilation of timing is safe

Shoot I don’t think my set came with the Variator lock

 

[koalar]

This bit

Not a great photo

Without it you can be just about half a tooth out, no big deal

 

[Pugglt Auld Jock]

When filling with coolant, get the concentrated stuff. Pour the correct percentage into the system and top up with water. I use water from dehumidifier as it’s effectively distilled. This way you’ll not over dilute the coolant.

That's how I used to do it but had a problem a couple of times with thermostats not opening on initial start up - very worrying as the top end of the engine can overheat locally which is not good for head gasket. Must say, I've not had this particular problem happen on any of the Pandas though. I concluded that the concentrate is rather more viscous than when diluted and was failing to get through the wee air hole in the thermostat thus causing an airlock? Some thermostats have a wee jiggle pin in this hole and then found some thermostats don't actually have an air hole at all. Following this I now premix concentrate with Halfords deionized water (cheap as chips in 5 litre containers) and have never had this problem again.

I was just thinking, as I am writing this, that coolant circulation has changed quite a bit over the years. On older engines the water which circulated through the heater matrix was actually physically blocked by a tap (hot/cold lever on dashboard heater control) if you wanted the heater to blow "cold". Whereas now a days, its usual for the water to circulate through the matrix all the time with air flow being controlled by a flap which either allows it to enter the vehicle interior or diverts it. The relevant point being that coolant now circulates through the heater matrix all the time. I would guess air locking of the thermostat is far less likely so the problems I experienced back then would be unlikely today?

Of course, using premix always introduces the problem that you may have some old coolant left in the system or even some plain water if you've been flushing the system. I always mix antifreeze concentrate 50/50 with water - distilled preferably but often deionized if I can't get the distilled easily - so it's a pretty "rich" mix which considerably exceeds any likely lowest temperature you'll get in our "temperate" climate. Using premix like this, if some neat water is still in the water jacket, could slightly dilute the additives in the mix, but I've never seen any problems caused by it - not even in the Imp engines which were well known for head gasket problems.

 

[Pugglt Auld Jock]

This bit

View attachment 449753

Not a great photo

Without it you can be just about half a tooth out, no big deal

As folk will know from my other posts I've made, I prefer to check the cam timing is correct using the locking tools before I start dismantling everything, and if I find the timing to be correct with the old belt fitted then I don't slacken the variator pulley bolt but mark up the pulleys with tippex and use these marks to align everything while I fit the new belt. If I'm not in a hurry I then recheck the timing with the locking tools just for reassurance. It's very easy to get the timing one tooth out though so you do need to check carefully before starting up.

I'm saying this because I've not yet had one where I needed to slacken the variator pulley bolt so never needed to lock the variator pulley with this wee tool. Having said all that, I believe this wee tool is there to stop the pulley moving as you tighten it's bolt, it serves no other purpose? If you're doing this - slackening or tightening the variator pulley retaining bolt I mean - remember you must NOT have the cam locking tool installed in the slot in the other end of the camshaft when slackening or tightening it and you'll need to hold the camshaft itself with a suitable tool to stop it trying to rotate as you tackle the bolt. Another reason why I avoid slackening this bolt if I can possibly avoid it.

The point of all the above "ramblings" is that I think the only function of this wee tool is to lock the pulley so it can't rotate while you're messing with the retaining bolt, it doesn't actually "set" the timing in any way?

Edit. Agree with Koalar above that a few thou off the head is pretty much irrelevant as far as varying the valve timing goes. Would be something a Formula 1 or top fuel drag racer would worry about but not us with our simple wee Pandas.

 

[DaveMcT]

I do get the point but I’ve never had an overheating issue. I have had difficulty bleeding the 1200 but the solution being bled is thinner up there so I don't believe under-diluted fluid was the cause.

 

[koalar]

The heads been skimmed

With the cam installed there is always 2 valves open, so it has to come out

You are supposed to take the variator off and lift the cam upwards, to avoid risking damaging the bearings, I don't know if this was done or even if the cam will pass though where the green arrow is

The variator locking tool also located against this shoulder, red arrow, it set the tooth exactly and also stops the two from spinning as it's tightened, without it it can be a maximum of half a tooth out

As long as the machine shop has used both the cam and variator locking tools, likely, then there is no need to touch the bolt on the camshaft again, but any previous timing marks maybe way off, but it also possible the machine shop randomly just tightened expecting it to be undone again during refitting, 70Nm is pretty tight on a T55


You can tell if the trimmings out by one tooth if you turn the engine over with the plugs in, it will hold the pressure, but you need to know what a good one feels like first

 

[Keepthe12alive]

This bit

View attachment 449753

Not a great photo

Without it you can be just about half a tooth out, no big deal

Sorry for all these questions, I am barely an amateur — do you know where I could get one?

 

[Keepthe12alive]

The heads been skimmed

With the cam installed there is always 2 valves open, so it has to come out


View attachment 449764

You are supposed to take the variator off and lift the cam upwards, to avoid risking damaging the bearings, I don't know if this was done or even if the cam will pass though where the green arrow is

The variator locking tool also located against this shoulder, red arrow, it set the tooth exactly and also stops the two from spinning as it's tightened, without it it can be a maximum of half a tooth out

View attachment 449768

As long as the machine shop has used both the cam and variator locking tools, likely, then there is no need to touch the bolt on the camshaft again, but any previous timing marks maybe way off, but it also possible the machine shop randomly just tightened expecting it to be undone again during refitting, 70Nm is pretty tight on a T55


You can tell if the trimmings out by one tooth if you turn the engine over with the plugs in, it will hold the pressure, but you need to know what a good one feels like first

Don’t think the shop used any locking tools — just reset the timing with the locking tools when I got the head back — am I in trouble?

 

[Keepthe12alive]

Like as is it seems the timing is generally right with engine turns though it might be half to a tooth off

 

[Keepthe12alive]

my mechanic did the timing for me, he seemed convinced that it was alright but might lose some power at high speeds or something