Technical 99% sure it's the HG, but looking for alternative causes

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Technical 99% sure it's the HG, but looking for alternative causes

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Hi guys,

Just driving home from work today, and noticed a slight hesitation when accelerating, with a slight judder. I pulled in at home and noticed that the exhaust gases were whiter than I would expect for a warm engine. When I opened the radiator filler cap, there was a lot of pressure and steam/smoke. Also, the level has dropped about 2 inches since last week.

Having experienced this before, I am 99% sure this is a head gasket problem (or even a cracked head), but is there anything else that would cause these symptoms?

If it is the HG, then that's not the end of the world, pretty cheap to sort on the old 8 valves. In fact, it's coming up for cambelt time anyway.
 
It's not old coolant, that is for sure. I replaced that last summer when I did the radiator. The garage confirmed my suspicions (there's no way I'm doing the work out in the street in this weather).

It is 35,000 miles since the last head gasket change, which seems a bit on the short side to say that I always ensure the coolant is fresh and at the right level. The only thing I can think of is that I used the longer-life 'red' coolant after draining and replacing the radiator. Now I know you should never mix red and blue coolant, but is there any fundamental reason why I should not use the red coolant over the shorter-life blue? Perhaps there is an incompatibility with the gasket and the more modern coolants.

The other possible cause is revving the engine too hard from cold. I haven't done this for a year since learning about it but perhaps the damage was already done from the previous year.

And don't worry, the oil, filter, coolant, head bolts, cambelt, tensioner and water pump will be replaced as well as the head gasket and skimming to the head. I look on the positive side, I might gain 0.25 HP from the greater compression due to the skimming :)
 
To be honest, it probably has more to do with the weather. Bear in mind that one morning, I started my car at -15 degrees celsius, and within 15-20 minutes it was sitting at operating temperature of 65ish degrees. That's a temperature gradient of 4 degrees a minute, which is a lot of stress on the head gasket, even though I didn't rev it. It was so cold that after an hour of driving, with 100% concentrated screenwash, I still could not use the windscreen washers because they were frozen. As a result, I've changed my screenwash to that Sonax stuff rather than supermarket concentrate.
 
Perhaps it was just one of them things, no fault of my own. I had to laugh, there's an advert at the top of this page from K-seal head gasket repair... err... no thanks, I'll do it properly (or rather have a garage do it properly because it's too cold for me to be bothered, and I don't have a cambelt tension tool)
 
Got the car back from the menders, £388 later. I enquired to find out a possible cause, and was told that the thermostat was sticking (and subsequently replaced). I had suspected it might be stuck open because the car took longer than usual to warm up in the mornings.

Now I could understand why a stuck closed thermostat would wreck the head gasket, but stuck open is a little more difficult to explain. However, because it was taking ages to get to temperature, perhaps I was a little premature giving it the berries as soon as I felt heat from the blowers. Due to the shortness of the slip road at this point, I didn't have a lot of choice. Now that the thermostat is sorted, it should be up to operating termperature before that part of the road.

So, lesson learned, if you suspect your thermostat is sticking open (taking longer than usual to warm up), be patient before letting the revs climb, and fix the thermostat as soon as you can, just in case it decides to stick closed instead. I'm just glad I've found a reason for failure at 35,000 miles since I adore this engine and wouldn't like to think there were inherent faults.

Plus, skimming = greater compression = greater power, yay!
 
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