Is250 Headgasket Replacement Cost

[james250]

Anyone know roughly what kind of price a dealer would charge for an headgasket change on an IS250? Preparing myself for worst case scenario. I have just purchased a Blockchek tool that analyses coolant for combustion gases. If combustion gases are present in the coolant system then signs of headgasket leak. I am concerned that I may have a very minor leak, not enough to contaminate the oil or coolant but enough to get some pressure in the cooling system on cold start to push the coolant out of the radiator neck. On a cold start with radiator cover off, the coolant should not gush out as there should be no pressure present like the following video:

But when i attempted this almost a year ago, i had coolant gush out which seems like the combustion gases might be escaping and into the coolant system.

[is200 Newbie]

Water should be moving round the system which is an indication your water pump is working fine - when cold I would not expect it to gush out but when hot I would expect it to do so.

I think the heat kind of pressurises the system to some extent - hence the need for an expansion tank. The expansion tank would act as a "breather" as you can see that on the cap you have two hoses - one connected to the system and the other free so any air in the system or over pressure will be bled through this tank through the hose.

Is your breather pipe in the expansion tank blocked? I would have thought that if the system was creating too much pressure then something would need to give. Also if you look at the expansion tank cap it will blow quite easily if any pressure was present, its only a push on cap.

Could the wrong coolant have been put in at some point?

Think of a kettle when its on - where does the pressure go when its starting to get hot - pushed through the spout as steam - Your system will be pressurised to a point but when hot - if you want to check this then take the rad cap off when hot but be very careful as it will be hot and will spurt out.

If your head gasket was leaking then you should see some signs of this.

Oil level high / coolant low (coolant in oil)

Oil creamy like mayo

Coolant overly discoloured (oil in coolant)

Oil level low / Coolant high (oil in coolant)

No coolant or low coolant (no heating in car)

No coolant or low coolant (car overheating)

No oil or low oil (car overheating)

Wet oil stains on the outer head casing.

[steve2006]

Personally I don't see a problem there, the water pump will cause slight surges as the coolant passes around the system.

Does the temperature gauge maintain a steady mid position, any other signs like coolant loss?

Generally with a HG fault coolant will be lost once the engine is turned off and the pressurisation of the system will force coolant back into the effected cylinder or oilway.

If you have no signs of cross contamination between coolant and lubrication and your still convinced of a problem I would have the engine subjected to a cylinder leakage test where each cylinder is pressurised with compressed air and the presssure then monitored over a period of time.

If the pressure is maintained this would indicate the engine is pressure tight and there is no problem with the gasket or valves.

[james250]

Steve, the temp gauge is always just below the half way mark. I had an overheat issue 5 months ago but it was due to a faulty pressure cap, which was replaced and temp issue has been fixed and consistent since. I dont have any coolant loss, except a little over a long period of time like 5 months which overflows from time to time through the expansion bottle. Oil looks clean and so does the coolant. I've already ordered one of those coolant testing kits to test the coolant for combustion gases, so i guess when that comes I can give that a shot.

[james250]

I just went and did a visual inspection in the engine bay. Coolant looks visually clean. It's about 3 or 4 cm below the max line in the expansion bottle. Every month or two i wipe away some coolant from the expansion bottle that overflows out, but its very little amount.

Looked around for visual oil leak signs but cannot see anything anywhere. Inspected oil dipstick and oil filler cap for any signs of coolant contamination, but oil looks like oil. No sign of any foreign matter.

Only thing i have a really tough time with is reading the oil level. From when i changed the oil to date, i cannot get an accurate oil reading, sometimes the dipstick makes it look like the oil level is too high and other times it makes it look like its too low. It cannot be low already can it specially since i only did the oil change about 1.5k miles ago.

[steve2006]

The kit sounds a good idea to confirm, if you have a friendly MOT tester locally they are normally happy to test for combustion gases in the overflow tank using their lamba probe.

I've never come across a HGF on an IS250 only the 220d.

I have the same problem reading oil levels on my LS400 the new oil is nearly clear and doesn't show up well on the dipstick.

[james250]

Lots of people say to check oil level from cold when cars been sitting for a long time. But the car user manual says otherwise. It says to check it with the oil at operating temperature, turn car off and let sit for a few minutes to allow oil to drain to the bottom of the engine. Is a few minutes enough for the oil to drain to the bottom and get correct reading?

[steve2006]

I always check mine cold, you have to anyway when you've just done an oil change, put in approximately the correct amount by measurement,start the engine to allow to circulate and fill up the filter,switch off engine and wait a few minutes before checking on dipstick.

Automatic transmission fluid level check proceedure is always taken hot for an accurate reading.