Possible HGF

[Dave B]

Seem to be loosing a little water with no signs of leaking. First thoughts are slow leaking head gasket. ( car still pulls like a train ). Local brit workshop talks about re- torquing the head. Never heard of this before, is it something that should be tried?

Dave B

[David Brown]

If it's a K series, I don't think you should be re-torquing the head. These are stretch bolts that are tightened in a particular sequence, taken beyond their normal tightening limits and, as they are stretched, cannot be re-used. I can't remember the torque values they are taken to and the extra beyond that, but look elswhere for resolving your problem.

[Graham D]

Take it easy, one step at a time. Start at the simple end of the spectrum and work your way to HGF.

Check all the connections very carefully for leaks and tightness, particularly if you are using silicone hoses. Is the oil clean? Is the coolant still clean?

Don’t over fill the expansion tank. The volume of air in the expansion tank is compressed as the engine gets hot, the smaller the volume the higher the pressure. The pressure cap (safety valve) will release excess pressure, but you will loose coolant as a result.

I wouldn’t touch the cylinder head bolts. I don’t think retightening of the bolts is normal for the K-series, if that's what you have.

If the engine is running OK, just closely monitor the situation for the next few weeks, it can’t do any harm (famous last words).

 

Graham

 

Edited by - Graham D on 27 Jun 2013 15:52:47

[charlie_pank]

This may be a silly question, but how do you know you're losing coolant? My assumption is because the level in the expansion tank is different from how it was when you checked it last.

 

Did you check it when the engine had been cooling for the same amount of time as last time? Maybe you had an airlock before, that has now been filled? Are there any telltale signs of leaking (normally a white residue). The most common spot to leak is at the point where the water-rail meets the block on the exhaust side...

[Dave B]

Have been away from computer for a few days so sorry for not updating. Thanks to all for their comments. Car is indeed K series and the problem is that before a blat, engine cold I top up water which has an antifreeze additive ( local sourced, put in neat ). After a blat of say 60 - 100 km, put car away until next time. Few days later check coolant and needs topping up, probably about 200ml. This happens almost every time. Coolant appears clean as does the oil. After reading many threads on here I was heading down the HGF route. I would love to be proven wrong as I dont think I would trust anyone here to tinker with my baby and getting the engine back to UK would be very expensive, unless of course someone fancies a cheap holiday in Gran Canaria!!!!!!

Dave B

[Rj52car]

This guide is from www.mg-rover.org hope it helps.

 

First Step - Be sure the Head Gasket has actually failed.

 

The Rover K series engine has a bad reputation for HGF and it is all too easy to jump to the conclusion that it has failed without first exploring the other possible causes. Before embarking on this expensive and time consuming work, lets first make sure the HG has indeed failed. The gasket seals the joint between the block and the head. At this joint there are four fluids, which need to be kept separate: lubricating oil, engine coolant, combustion gasses and lets not forget the atmosphere. It is most normal for the gasket to fail between the coolant ways and the oil ways but other failure types are known. For the head gasket to have failed you must have one of these symptoms.

 

Coolant in the oil – The gasket has failed between one of the waterways and one of the oil drain ways. A sure sign of this is coolant loss together with murky dark coffee colour oil, with flecks of cream. You will also be loosing a small amount of coolant. Don't confuse this with a little bit of mayonnaise on the dipstick above oil level which could just be condensation but in this case do watch keenly to see if this develops into something more serious. The picture shows my oil in the pan after it was drained. It had been changed one week before and I had lost only 1cm of coolant from the reservoir.

Oil in the coolant – The gasket has failed between the high pressure oil way feeding the camshafts and a water way. The oil is at a higher pressure than the water so escapes into the cooling system and finds its way into the coolant reservoir. Coolant should normally be sparkly clean. Again don't confuse this with dirt in a poorly maintained engine or residue from a previous failure. Flush the coolant system and monitor the condition to see if it gets worse.

 

Steam from coolant cap whilst there is still coolant in the reservoir – The gasket has failed between a cylinder and a waterway. High pressure combustion gasses are escaping into the coolant system and displacing water. The system will pressurise and the relief valve in the cap will blow. Don't confuse this with a typical overheat scenario caused by poor coolant circulation, dodgy radiator, stuck thermostat or blown radiator fan fuse. Check that your radiator fan is working and that there is no air in the radiator or heater circuits. Bleed the system, start the engine and rev it. After 1 minute, stop the engine and open the coolant cap. If there is an unexpected pressure, then that's the confirming symptom. Garages also have test kits to analyze the coolant to detect the presence of exhaust gasses. Well worth it if you are not sure.

 

Loss of coolant Only – This is the $1000 question. It could be that the head gasket has failed between a waterway and atmosphere. This is most common along the front of the engine above the exhaust manifold. It should be possible to see some witness or staining from the leak above the heat shield. The more likely cause of water loss is a bad hose joint, leaking hose, under pan coolant pipes, water pump gland or the radiator. It should be possible to see some water dripping somewhere. Put the car onto a dry surface or some newspaper to see where it might be dropping. Exhaust all other possible causes before concluding it's the head gasket.

 

Following the four fluid logic you may conclude that it is possible for combustion gasses to escape to atmosphere or for oil to escape to atmosphere. If you look at the configuration of the gasket however, there is no interface between gasses and atmosphere or oil and atmosphere. If you have an oil leak in this area, it's not the HG, more likely the cambox.

[TomGaval]

Check the gasket at the water rail to block. Maybe the water rail just needs tightening up. Tom

[leon]

once you have exhausted water rail and all hoses next check for me would be the inlet manifold gasket. I was in a similar situation with water loss and no sign of a leak from hoses, sniff test said no hydrocarbons in coolant so after much head scratching final conclusion was inlet gasket which proved correct. Particularly likely if you have the plastic manifold.

[Ed W]

I would go along with the advice given so far. I had a leaking water rail, pin hole where the front bracket attaches, and also a leaking inlet manifold gasket. Symptoms included white smoke on start up see Angus website here.

 

Ed