Right back to where I started four years ago

[ukkid35]

This is last time I'll be driving my car for a while, as I now have foaming coolant in the expansion tank

[ukkid35]

Joolz got 410 out of mine, despite the corroded liners, and 18% compression variation, and worn lifters, so I'm not looking to upgrade anything other than reliability.

I have a theory about the cause of HGF, but it's just a guess, I'd be interested to hear other suggestions.

Firstly my car does pink briefly if I'm not gentle with the throttle around 2k. Joolz got rid of most of the pinking, but a little always remained, exacerbated by hot weather or traffic. I think this has probably weakened the HGs.

Secondly, I have run low on coolant several times for several different reasons. I had a rad leak and didn't realise. That was two years ago and probably the worst overheat, because I didn't believe the temp gauge (I'd only recently had it repaired and I assumed it had gone wrong again).

On another occasion my car dumped most of it's coolant through the expansion tank cap relief while in hideous traffic in Luxembourg. I think that was due to the temp sensor under-reading, and therefore failing to switch on the fans (it would show 70C while cruising using the diags).

Over the last couple of months it has simply being over-pressuring, and expelling coolant. I have replaced the temp sender, and thermostat, and expansion tank cap, and each time the symptoms got a bit better. Probably because each had been damaged due to the system overheating. Each time I hoped it had been cured, because I wouldn't loose much on a run, perhaps just a cup or two.

However, by the time I got to the Ring on Wednesday, it was using a litre per hour. By the end of the second day it was using 2 litres a lap.

I didn't let that stop me have a brilliant time, because it was no different to drive, other than a little harder to start, presumably because it was sucking coolant in to the cylinders when cooling.

I am really not looking forward to taking the heads off again. At least I know what I'm letting myself in for this time.

[ukkid35]

djstevec said:

On man....gutted for u pal

ANY help you want, just holler.....gotta keep that one on the road/track

Generous to a fault, Steve. And I will take you up on that when I have to put the heads back on, I will need you to help keep me focussed again. Thank you.

[ukkid35]

Thanks Aide, that really is very generous. I know from past experience that unless the car is close to where I'm living, I'll never be spend enough time working on it. So I will persevere in the shared garage, they are used to me working on the car now, and most of my neighbours stop to chat when they see me there.

Also, I still need to return your MBE!

[ukkid35]

gruffalo said:

Willing pair of hands here if you want to make a start tomorrow.

Also can do Monday evening and Thursday evening as well.

Thanks Martin, again a very generous offer, and I will keep that in reserve for when I really do need an extra pair of hands. Refitting the gearbox is one of those times, and when I get there I'll be on the home straight!

[ukkid35]

jammy_basturd said:

It seems I had exactly the same issue. Coolant system that wasn't in brilliant condition, led to the engine running hot which eventually blew the head gasket. I don't have the time nor equipment any more to spend doing major jobs like that on mine so unfortunately I sold it a few weeks back.

Sorry to hear that, I hope you got a good price for yours. And thank you for the parts - much appreciated.

[ukkid35]

julian64 said:

where are you based?

I'm near the Ace Cafe, walking distance really.

[ukkid35]

My car is back in its natural habitat at last, a foot off the ground on axle stands (of course this is not typical of other Cerbs, only of basket cases that are tracked to death)

[ukkid35]

I'm really hoping I can get it all done by the end of September in time for DN13. I'm going to the EdFest in a weeks time, so that isn't going to help, but I have all of September free. No intention to get the heads skimmed again, not that there's enough left to skim anyway, so that will save time too. The cam timing part still scares me though. Might as well replace the cam chain this time too. Got to decide whether to faff around getting the manifolds ceramic coated, really not sure.

[ukkid35]

The evidence piles up

The oil seep from headgasket around cylinder 1
No soot in exhaust port cylinder 1 (unlike all other ports)
Endoscope showing damp inside cylinder 1 (not so easy to see but definitely glistening)

[ukkid35]

The teardown continues at a good pace



I hate AJP8 head bolts with a vengeance

[ukkid35]

Work so far

Evening one - lift and remove under trays
Evening two - remove exhaust and propshaft
Day three - remove cooling system
Day four - remove induction system
Evening five - remove gearbox

I'm typically spending 3-4 hours each evening and 6-8 hours each day. I am glacially slow I know, but this is lightning fast compared with my first attempt.

[ukkid35]

julian64 said:

Why take the gearbox off to take the engine out?

If you've gone to the trouble of getting the propshaft off why not lift the engine and gearbox out as a single unit?

I don't have the option to pull the engine, because of where my car is I have to work with the engine in the engine bay. This is a pic from four years ago, and where I should be by Thursday.

[ukkid35]

julian64 said:

I think you are some sort of masochist. Mike (Saunders) and his dad used to tell me they could remove the engine and gearbox (together) from a cerb in a little less than an hour. I've never managed that, but it took me less than a days work.

Having done that all your problems would virtually dissapear. I stripped an AJP8 down to individual components in a weekend. Its so much easier to apply tools and get bolts out without breaking them with the engine in front of you.

Engine hoist would cost peanuts to rent, and all your problems with trying to work round a Cerb in a tight garage would also dissapear. You'd stop buusting your knuckles, damaging the various bits of the engine, and have a morew fun time of it.

Hats off to you that you want to do it in this way, but I really can't see why you'd want to.

We had that discussion four years ago, and nothing has changed since then. I still work on my car with the consent of my neighbours, and I will not do anything to risk upsetting them unnecessarily.

[ukkid35]

julian64 said:

God I'm getting old. .

Anyway I asked where you were because if you were in spitting distance to brands hatch I was gonna suggest you come over in the car where I have all the bits to help you take the engine out.

Thanks, I'll save that offer for when the bottom end (or pumps) go, because then I really will be stuffed!

[ukkid35]

You really do need to lift the engine by about six inches for the timing cover to clear the chassis rail (so not possible with the gearbox attached - possibly three inches lift otherwise). I doubt titling it would work, and once you've got the propshaft off you might as well pull the gearbox (although that does mean you have to put it back which is much more awkward - I need a friend to help me manoeuvre the gearbox while my gf presses the clutch).

[ukkid35]

Definitive proof of HGF, this time. No obvious sign of failure last time.

Perhaps four years ago it was simply much earlier and less obvious to detect, this time I did run the car until it was losing 2 litres per lap of the Ring.





It was cylinder 2 that failed, here are my compression numbers from four years ago

1 235
3 225
5 235
7 260

2 255
4 260
6 245
8 245

So it is possible that pinking played a part, and it is also the where one the front 14mm head nuts has to work, and I had issues with the weld failing on the tool I used.

So perhaps this is a combination of factors:

Incorrect head nut torque
High compression and pinking
Overheating
Track use

I also have an oil leak from around cylinder 1 where oil feeds the head, and where the other 14mm nut is.

Bizarrely I am quite pleased to see that it is HGF, because at least I know that a new pair of gaskets will enable me to use the car again. Last time I was confused and annoyed when it continued to lose coolant after replacing the head gaskets.

This time I have decided to fork out for a new duplex cam chain, that and the much higher cost of gaskets means that my parts cost is now a quite significant sum at £400.

[ukkid35]

A couple of weeks ago I cleaned up the heads only to decide that they could not go back on without another skim. I really wanted to avoid that as I really don't think there's enough material to do another skim. But the area under the fire ring where the gaskets were leaking has causing significant damage, and ignoring it seemed like a fools paradise.





I took them to a truly eccentric outfit recommended by Charlie at SRR, and they seem to have done a reasonably minimalist job, but even so it's still cranking up the CR and making it even more difficult to refit the timing cover and injectors/fuel rail.

I'm bracing myself for more pinking and I'm planning another trip to Joolz for a remap.

However I need to put the car back together before I can get up to Chesterfield, and I have DN13 booked in just 17 days time. If I can get back to the Ring for DN13 it will be a real accomplishment.

[ukkid35]

jammy_basturd said:

I know you prefer to keep costs down, but for the sake of saving the cost of another rebuild further down the line, could you not either see if anyone has some second hand heads, or alternatively get a custom, thick head gasket made up, or a spacer?

James you are absolutely right. I should definitely try to get some custom gaskets made, or find some replacement heads. Either would be a very good idea, but I have sunk a fortune in to DN events this year, and although I had a brilliant time in the 928 when the T5WC failed on the way to the Ring in April, I don't really want go back in the elderly 230k mile Porsche again this year. So I need to have a working car again in a matter of days (and I absolutely prefer to keep costs down).

However, worst case scenario and the engine runs like a dog, where do I get custom gaskets? Who makes them - Cometic?

I think custom gaskets would be less impossible than finding replacement heads - I'm assuming they don't really exist unless you buy a whole engine from one of our favorite Northumberland based scrap merchants.

Just between you and me, I just trashed a new head gasket on Friday because I only seated one head before torquing it to spec. When I fitted the second head I realised that I'd used two incorrect size washers under the inner kaylocs - Noooooo!!!! That was a £140 mistake, luckily RG were open yesterday so I could go buy a replacement, but it still hurt. I've done this job before, so I really don't understand how I could >?:@ it up so badly, oh well - only engine timing to go (I hate that job even more).

[ukkid35]

Gazzab said:

Andy at APM mentioned thicker gaskets to me once. I assume they are comtec (?).
On my car we had to take more meat off the heads and so to be safe we wired it and fitted copper gaskets. That was 2 yrs ago I guess and no problems.

This is a £500 repair for me. If I have to do anything more esoteric I would need to hand over the engine to someone else and it becomes a £5k job, which is not an option. It would make more sense for me to buy a used engine and try to make use of that than go for a high end rebuild.