Headers glowing red at tickover - what's up?

[victormeldrew]

I think its broke.

I had a problem with th engine mount, which led to coolant loss etc. See Flooded to the point of hydraulic lock.

Engine mount now replaced, and I got a new set of plugs. Whacked them in (what a pain) and she started up straight away; but something wasn't right.

First, very high tickover - 2000rpm.
Second, floods of water out of the pipes. Black, sooty water (not fuel, definately water.)
Third, after running for a couple of minutes, the header on no 4 cylinder was glowing red. Some of the others were starting to glow as well, but no 4 was REALLY hot. Red going on yellow.
Fourth, temp repair on swirl tank neck was holding fine, but hoses were very solid, the top pipe to the swirl tank you can normally squeeze, but it was solid as a rock with the engine running.

Blown head gasket? Broken rings? There is a quite loud ticking on that side. Do the symptoms sound familiar to anyone?

Please?

Apologies for multiple posts, I put this on the Griff forum by mistake.

[chassis 33]

Blown head gasket could explain the pressurised cooling system, but not really the EGT temperature.

Did you move/adjust the dizzy at all? Too much retard or too little advance will cause EGT to rise but lso increase torque/power at the bottom end which could explain the high idle.

Are you sure the leads are on the right plugs, sounds silly but you never know. Check check and check again!

Regards
Iain

[victormeldrew]

chassis 33 said:

Blown head gasket could explain the pressurised cooling system, but not really the EGT temperature. Did you move/adjust the dizzy at all? Too much retard or too little advance will cause EGT to rise but lso increase torque/power at the bottom end which could explain the high idle. Are you sure the leads are on the right plugs, sounds silly but you never know. Check check and check again! Regards Iain

Iain

Thanks. Yes, I did take the dizzy cap off to make sure it did get wet inside - it was in the direct path of the steam vent in my swirl tank. I'm pretty sure I put it back properly, peg aligned with indent, clips in place etc. Is it possible I might have twisted the dizzy itself? I can eat three weetabix! There is slop in the dizzy cap anyway, it will move probably a couple of degrees even when clipped down. Is that normal?

[GreenV8S]

In that case it wouldn't fire up at all? These symptoms point to severe misfire or massively retarded ignition I think. Strobe light would tell you where you stood on the ignition timing front.

[chassis 33]

GreenV8S said:

Strobe light would tell you where you stood on the ignition timing front.

...assuming the timing marks on the crank pulley are to be believed, I've been stung on that one before!

Regards
Iain

[Cider Andy]

It's a puzzler this is, VictorMeldrew. Obviously you're upset that it's going to cost a few quid to repair one way or another, but I have to ask the question: when the swirl pot got holed, how far did you drive it without water?

We must assume that nothing other than the coolant system being ruptured happened. So, unless you know different, there have been no changes in ignition timing or anything else that's normally fixed?

After repair, a couple of manifold branches glowed, there was sooty water in the exhaust and the coolant system was pressurised enough to burst the radiator. This would suggest a blown head gasket or two. I suspect that after the compression stroke and during the exhaust stroke, the mixture is still burning, perhaps because it contains some water. Hence the massive rise in temperature in the manifold(s), in no. 4 branch in particular.

Hopefully, a head gasket (or two) will have you back on the road.

[victormeldrew]

Cider Andy said:

It's a puzzler this is, VictorMeldrew. Obviously you're upset that it's going to cost a few quid to repair one way or another, but I have to ask the question: when the swirl pot got holed, how far did you drive it without water? ... Hopefully, a head gasket (or two) will have you back on the road.

Not far; I'd just popped into town when it went (a speed hum put the finishing touches by the way , but it was going to go at some point), and this is only 3 miles at most. The engine was cold when I started, and I drove it very gingerly back in as high a gear as possible, keeping the revs down and the airflow up. I know they develop a lot of heat, but I do have an oil temp gauge fitted as well as the water temp, and neither registered anything excessive (though the water temp obviously couldn't be trusted at this point!). The wife was following behind and I was leaving a vapour trail, but the steam only really started pouring out in the last few hundred yards, as presumably the thermostat had opened by that point.

I don't think it was the heat. I'm 99.99% certain the hydraulic lock was excess fuel, and this is what did the damage. I'll know better tomorrow after I get the heads off.

[victormeldrew]

GreenV8S said:

In that case it wouldn't fire up at all? These symptoms point to severe misfire or massively retarded ignition I think. Strobe light would tell you where you stood on the ignition timing front.

I've got a strobe somewhere, I haven't used it for years though so I'm not sure where! I'll have a quick look before I start stripping her down.

Not sure that I'd see just the one pipe glowing hot though with retardation; surely they all would? Bent exhaust valve is looking favourite for that, with the flame front extending up into the header.

[blujay10]

Very sorry to hear of your troubles, and good luck with the repair. Looks like you know what you are doing so I guess you will be able to keep the cost down! Would be interested to hear how you get on....

[thegamekeeper]

I have often found that overfuelling to the point of hydraulic lock will blow the headgasket and sometimes even suck it into the cylinder depending at which part of the cycle it actually fails. It is logical when you think about it, you can compress the gas, ignite it and produce power. Internal combustion engines are not designed to compress liquid. If the gasket has gone catastrophically you will have cylinder pressure leaking into the cooling system, blowing the rad, which was probably on the way out because it was obviously the weakest part of the cooling system. You now have exhaust gasses leaking across the head face which will cause the manifold to glow red, and will melt eventually. The worst scenario and well worth checking while heads off is they often (usually) bend the con rod as well, but hopefully the gasket will have failed soon enough to releas e the pressure before it built up enough to bend the rod. Happy days!! ps make sure you fix the overfuelling before running after repairs or you will start the repairs again sTeVeR

[victormeldrew]

thegamekeeper said:

ps make sure you fix the overfuelling before running after repairs or you will start the repairs again

Now that would be embarassing wouldn't it! Yes, I will be testing the injectors quite carefully, but thanks for the reminder!

Just checked your profile - I hadn't realised who you were.

How would you recommend checking for rod damage? Would meauring the height of the piston crown to the cylinder deck be a reliable indicator of rod bend, or will the pistons be at variable heights anyway?

>> Edited by victormeldrew on Thursday 24th November 10:58

[thegamekeeper]

Sorry about the delay in replying, had to dig PC out of snow drift.Checking for bent rods can be easy or it can be hard. If they are very bent it should be obvious because one or more pistons will not come as far up the bores as the rest and you will see it visually. If they are not as bent you will need to measure with a dial gauge and micromtere. All the pistons at TDC should come exactly the same distance up the bore. You will need to measure them all to check if any are significantly different.
Dont be tempted to assume they may not be bent, check. The loads on a piston and conrod when it changes direction at 6000 rpm are collosal. It changes from going at several hunded miles an hour in one direction to the same speed in the opposite direction 6000 time in a minute with an explosion above it when it comes up and a big heavy flywheel's inertia trying to break it at the change of direction at the other end. Conrods are only strong when they are dead straight so any deviation from straight will seriously weaken it and given the above you can work out the rest.
Not wishing to spoil your day any more there is also the strong possibility of broken piston rings.

I have over the years had a few cars which have looked like just a head gasket but have been serious and others which have been lucky. I had one 400SE which did slightly less than 3 gallons to the mile ( it ran out of fuel before it had done a mile )and when I stripped it it had 12 litres of oil based liquid in the sump so whatever happens and however far you need to investigate, and it should go without saying change the oil and filter.Hope you are lucky and if you need any more councilling feel free to ask sTeVeR