Possible head gasket failure?

[TomE]

Wondering that I might be the next victim of HGF and the more I read on here the more I'm thinking myself into that scenario. Will be getting a head block test done asap but thought I'd describe the symptoms in case anyone recognises them as something obvious and not HGF (crosses fingers!).

I've a 1991 SE with low mileage of 35k (seems v low for HGF?), regularly serviced by Lotus dealers then Lakeside and Plans. Due to the low mileage I've serviced on time interval and at least a B service every year (plus C, belts etc per the factory spec). BBR conversion from new. PECO exhaust (and therefore higher max boost of 0.95) since last September. Done 1-2 trackdays per year for last 8 years, mostly at Goodwood which has three long straights on full boost.

About 18 months ago started getting small patches of coolant on the garage floor. No obvious fall in coolant level though, and patches didn't grow if the car was parked up, so didn't seem likely to be a static leak in a hose or clip.

Serviced by Plans last September, who pressure-tested overnight and found no leaks but nevertheless checked hoses and tightened clips. They noted some old deposits around a couple of clips.

Since January its been needing a coolant top up of 200-300ml roughly every month. On Saturday I checked the level (OK) and headed to Goodwood for the Club Lotus track day. After my seventh session as I pulled into the paddock the fan came on - doesn't usually do this after my cool down lap (no brakes, no turbo boost) so turned engine off but left ignition on. Temp gauge continued climbing off the scale, so bonnet up and immediately noticed dried coolant deposits radiating out from the expansion tank cap and across the hoses and components at the top of the engine bay, plus on the underside of the bonnet. Damp below the expansion tank and on the underside too.

Eventually after I left it to cool completely it needed 2 litres to top the cooling system back up. Car then idled at normal 1/4 temp so drove home keeping a careful eye on the gauge, which only went a whisker over 1/4 the whole trip. But checking it fully cold on Sunday it's lost 200ml in the 40 miles home.

Assembled Elaners at Goodwood thought possibly the valve in the expansion tank cap had gone. My car's got a black cap with a seperate black disc with two holes through it, but not all the other M100s had this.

Reading through the Ancillaries and Engine threads suggests the valve could be a possibility. But it also suggests this may be a symptom of early stages of HGF, with the combustion gases blowing through into the cooling sytem and over-pressurising the system which fails at the tank valve.

Aside from head block test and visual inspection of hoses/clips, what else should I be checking?

[Gazza]

I was topping mine up for weeks and noticed bubbles in the expansion tank water, where the gases were escaping.

Make sure car is completely warmed up and running when you do the test.

Good luck

Gazza

[TomE]

Make sure car is completely warmed up and running when you do the test.

Thanks! I don't know the ins and outs on this - what difference will it being warmed up make? B&C said they'd wait until it had cooled from me driving it over before doing the check for combustion products in the coolant.

[Monty]

Tom, sorry to hear of your problems but it does sound like a HGF and a Block test will soon confirm.

I had the same and only when i was on track would it show it`s ugly head other times the temp didn`t move on a normal drive. Thats why i`ve said that they`ll be others out there who won`t even realise there HG is failing and could even be years before they notice


Hope you get it sorted soon

[L.G.]

If you were to lose that amount of water because of HGF shouldn't the engine develop other problems? I mean rough running on cold start or too much water out of exhaust?

This is not a question to Tom btw, it's for open discussion.

L.G.

[dunnlor]

If you were losing that much water due to a head gasket, I'd have expected your exhaust to be white from the steam, or water droplets in your oil.

Any leakage from the water pump?

[TomE]

If you were to lose that amount of water because of HGF shouldn't the engine develop other problems? I mean rough running on cold start or too much water out of exhaust?

I think that might be true if you lost 2 litres in a day of normal running. But I did 120 miles on track, with roughly 50% of the time at full turbo boost (0.95 with the PECO) and upshifting at 6000-6500rpm. So overall pretty stressful on the engine.

Many years ago when my wife had HGF on her Fiat, it went from cooling side into combustion side, which gave very few early symptoms and suddenly ground to a halt with water in the cylinders. From what I've read, the Elan failure mode seems to be more commonly the other way, from combustion side into cooling.

This means there are puzzling cooling-related symptoms early on and I suspect if you managed to keep enough coolant in the system and topped it up all the time, it would keep running for quite a while without major incident. I'd guess it's only when the over-pressurising boils off enough coolant that you get consequential problems due to general overheating and localised hotspots, which might ultimatley cause a sudden failure somewhere.

I'm surmising it's the hot, high pressure combustion side breaching into the less hot, lower pressure side that boils off the coolant into the atmosphere. Little if any coolant crosses over into the combustion/exhaust, so you don't see symptoms like water in the oil or water vapour in the exhaust.

If you try and contain the over-pressure, eg higher-rated expansion tank cap, then the pressure is just going to seek out the next weak point. If you're lucky that might be a hose clip; unlucky and it'll be the rad.

I'm wondering if there's some precautionary advice as a result of this: if you've had unexplained coolant loss or noticed dried coolant spattered around the expansion tank or hose joints then ought to do a bit more investigation.

[chris.t]

Tom before you panic!! have you checked that your thermostat is working properly. If you have elanScan this is easy to check. Otherwise just drop a new stat in and see if things improve.

Also is the cap on the header tank knackered. Remember that the system is meant to be under pressure. if the system is open to atmosphere cos of the cap being knackered it will boil.

Cheers Chris

edit/ i have wheel bearing probs since the TD so i didn't escape either!!

[TomE]

Thanks Chris, will check the stat too. B&C had the car today while I was up at the factory with their sales guys. Contradictory indications so far: minor fail on the block test but no oil in coolant or coolant in oil; header tank cap partially failed and some weeping on hose joints where connected to tank.

They've recommended that I replace the cap and tank plus clean up hoses/clips that connect directly to the tank, and do a full flush and refill on coolant. Then we'll see if there's still coolant loss and re-run the block test. Parts ordered, so should get this done in the next couple of weeks. Will keep you posted.

Re wheel bearings, Lakeside somehow managed to sort my car out so that they no longer needed redoing after every trackday. Don't know what they did but (touches wood for umpteenth Lotus-related time today!) have been trouble free for last 3 years.

[Monty]

Tom,

Can`t see it being the stat as you said the runs at steady 1/4 temp, if it was a stuck stat i would think you would see this on the temp gauge.

When Pinky`s had its 1st HGF after a cadwell trackday the blocktest took awhile to change colour, so it was just the start of a HGF and the only symptons i got was a slight increase in temp, a bit off coolant from the expansion tank and a drip from the rad.
So it`s sounds like yours is the same and since you do trackday i wouldn`t bother with changing the cap or the coolant and just get the HG done.

I`ve heard `change the expansion tank Cap` before which IMHO is bollocks, i know Martin (texas) was told the same thing but i knew that he had a HGF which in the end turn out true.

[chris.t]

If coolant was getting into the exhaust at that rate you wold defo smell it. if coolant was getting into the oil at that rate you would defo see it. where else can it go?

[TomE]

where else can it go?

Cooling system being over-pressurised by gases crossing over from combustion side, boiling off the coolant out of the pressure relief valve and so out to atmosphere? It's the only explanation I can think of for the lack of evidence of coolant leakage elsewhere, and would explain dried coolant splatters around expansion tank lid and top end of engine compartment.

[TomE]

OK, so B&C have changed the header tank and cap then flushed the cooling system and refilled. Still getting a positive on the block test and over-pressurising of the cooling system. So basically it is HGF

Now I've got a big dilemma. I've a refundable deposit down for an Eagle for delivery in January but won't know until the Motor Show end July whether to commit to that. And following family discussions we're wondering whether to go for an Exige instead and reconsider the Eagle a year or two after launch. So the debate is whether or not to fix the Elan and whether to sell it/trade it in now/later.

B&C have quoted £2400 but to be fair they've allowed for several things that may or may not need doing, eg skimming the block and head, pressure testing the cylinders etc. Plus they've included the non-HG bits everyone reckons should be done (pulleys, belts etc). In all it's about 20 hours labour. Clearly that's worst case and I'd probably get Lakeside or Plans to do it - reckon about £1100-1400?

Anyone got any thoughts on whether the car is saleable/tradeable with the HGF unresolved and how much a buyer might expect to knock off the asking price it would've been if no HGF?

[Monty]

I did say that replacing the pressure cap was bollocks

B&C should have there balls snipped for quoting a silly price like that any garage can do the HG approx £500, skimming aprrox £20. You can get all the bits from Rockauto`s far cheaper than lotus prices.

Unless someone of here buys your Elan then you`ll be best off getting the HG done

[marcos]

same problem! do you know the best head gasket to use ?
I know , my wife's elan is 17 years old but it's the first car we own with
ageing head gasket !

[TomE]

Right, the car's in this week with Plans Motorsport for the head gasket and recommended ancillaries. Anyone know what the deal is on running it in after they've finished? Do I need to do a certain number of miles with a rev limit, and/or vary the load etc? Think I read somewhere that some parts need to be re-checked after a few hundred miles.

[WillB]

Interesting, I didn't realise Plans had experience with the Elan?

[Monty]

Right, the car's in this week with Plans Motorsport for the head gasket and recommended ancillaries. Anyone know what the deal is on running it in after they've finished? Do I need to do a certain number of miles with a rev limit, and/or vary the load etc? Think I read somewhere that some parts need to be re-checked after a few hundred miles.

IIRC it doesn`t need running in, infact if they fit the Lotus HG then you don`t have to recheck the head bolts.

In saying the above i`d just take it easy for the 1st 500 mile ie no high reving. Just to be on the save side you could check the headbolts after 500 miles but on the 2 HG (Lotus) i`ve done the headbolts did not budge.

[Paul.P]

Tom, read RIP's thread, ( Exploding Elan, in the Projects Thread ), it will tell you there's no need to run in, if its fitted properly !.

[rip]

Tom, read RIP's thread, ( Exploding Elan, in the Projects Thread ), it will tell you there's no need to run in, if its fitted properly !.

I think you are going from memory, Paul.

I cannot find any mention of HGF in that thread, nor running in on the other (righfully locked) EE thread.

You are correct though. Gerald told me that there was no running in necessary. It makes sense to me because there are no new moving parts. If you are also having something new fitted or replaced (valve stem seals for example), then this is another matter.

As for the price; it sounds a little high to me, although I think Monty's estimate is a bit low. If the head has to be skimmed, the manifolds should come off to allow good access to the head face (these would otherwise stay it situ). Gerald also took my cams out to ensure that the valves stayed closed in order to protect the head from swarf.
If this is the first time your HG has been changed & the head is pitted from corrosion (which often seems to be the case), it is likely that the engine's coolant jacket needs a good clean-out too. That would be another job to stick on the bill.