Losing Coolant Like Crazy - (Was:Headgasket Hell)

[Hectorious]

I have a 1997 Discovery 1 with a 4.0 litre gas engine that started running a bit rough and produced white smoke/steam out the exhaust with the classic smell of antifreeze. I suspected a blown head gasket but after finally pulling the heads today, both gaskets were intact and showed no sign of leaking coolant into the cylinders.

To me, this would seem to indicate a cracked block, allowing coolant directly into one of the cylindars, and not through a leaky gasket. But ... any other thoughts? has anyone had their cracked block successfully repaired, or is it time to admit defeat part the vehicle out?

[red90]

That is not really possible. It is an aluminium block with steel liners. If the block does crack it lets coolant into the oil. Coolant into the combustion chambers could only be a head gasket or possibly and intake manifold gasket.

[RichardV]

I had the same with my 4.0l Disco. Despite the head gasket being intact, put a new one on, tighten th head down and you have another 500km before parting it out.

[Hectorious]

Thanks Richard and Red.

I was quite relieved to hear it might/likely isn't a cracked block, and yes, i suppose if it was, the pressure differential would mean oil in the coolant, and I didn't have any.

The head gaskets being intact would suggest its not that where the leak is, but I will replace them regardless seeing as I have had the heads off anyway. As for the coolant getting into the combustion chamber through the intake manifold gasket, I don't understand how that would happen. Not that I doubt you are correct, I just don't understand the path the coolant would take. Can one of you explain?

Richard, your problem being fixed by replacing the head gaskets despite no sign of leakage, could that have been because you replaced the valley gasket at the same time and that's what did the trick?

[red90]

There are coolant passages next to the intake ports on the intake gasket. If it leaked into one of the intakes, you would get burnt coolant.

[VA7ZD]

Maybe I'm out to lunch but your head could be cracked. I just changed out a head on a Cummins 4 cyl that was cracked between the valves in no. 1 cyl. A Really good cleaning and some dye penetrant would most likely show it but the best bet is to take it to a head shop.
Regards
Ian

[Hectorious]

Update: I've replaced both the head gasket and the intake manifold gasket (AKA valley gasket). I'm getting a P1316 (misfire excessive emissions) error code and running a bit rough, with a slight lack of power. More telling, I'm losing tons of coolant, like 8 litres in the last couple of days. I'll go from full coolant and everything fine for about 20 km, then rapid overheating. So I'm definitely losing coolant to somewhere.

The real mystery is that the coolant is not ending up in the oil, and I've got no oil in the coolant. Also no sign of an external leak - no drips on the ground or steam from the engine compartment. The only thing I can imagine is that the coolant is leaking into one of the cylinders (likely the one causing the misfire code), and exiting as steam via the exhaust.

So I'm back to suspecting a cracked block or head. Is there any cheap method of confirming this, and if it is confirmed as the cause, any estimates on repair costs? I didn't pay allot for this truck and have only a mild sentimental attachment to it.

Thanks in advance (again),

Chris

[red90]

An engine shop should be able to pressure test the heads.

[ANDYD]

One other place to check for coolant leak is in the passenger foot well. Feel for damp carpet, sometimes runs down the footwell under the carpet so the upper surface appears dry but is wet underneath. This would indicate a heater / AC coolant leak.

Otherwise I would suspect the coolant is going out the exhaust somehow which seems quite common on these V8's.

[island dormy]

Hi Hectorious

If you are losing that much coolant with no puddles and no rise in the oil level it has to be going into the combustion chamber and out the exhaust there should be a visible white cloud behind you as you accelerate and you should be able to smell anti freeze in your exhaust. I was walking to town the other week and a mini van passed me with a white cloud of steam coming from the exhaust pipe and a moment later the smell of anti freeze was unmistakable.
Hope you find your problem soon the Van Isle Rover Rally is only a week away.

Victor 1962 Dormobile

[HeadDamage]

Not sure if this is relevant or not but my old 1987 RRC had a water line to the throttle body to prevent icing. Perhaps there is something similar on this rover and it is leaking into the air stream. Seems very unlikely but thought I'd throw it out there.

[RichardV]

I changed both gaskets and for whatever reason it worked. Both gaskets were OK but I change them anyway as was recommended to me . The coolant stopped coming out the tailpipe like sweet clouds. Apparently it only works for a short while. If your still losing coolant afterwards, the end is near?

[Hectorious]

So, since you are all up-to-speed on the situation with this truck, I don't feel any guilt about offering it for sale, as a project or parts truck. Replacement of head gaskets and intake manifold gaskets is about the limit of my technical competence. Repairing a crack in the block or heads is one step beyond ....

It's got brand new tires, new stereo with lots of bells and whistles, and a pair of Kicker brand subs in the back, and is in otherwise excellent shape. I'm looking to get $1800 for it, mostly to recover the cost of the tires and sound system. I'll post it for sale in the appropriate section of the Board soon, but if there are any early takers (Ha!), let me know!

Chris