OT: what would cause a HG failure on a ford 3.0 vulcan? long...

[ryan roopnarine]

The car is a 1999 ford taurus with 3.0 Vulcan 12 valve SOHC.
It has 170k miles/272k km on it.

I was driving down the highway with the cruise control set to 73-75mph on sunday. I disengage the cruise control, but when i try to resume speed, I hear what sounds like severe detonation. Just to clarify, I had begun to hear a rattling from the belt drive area several days prior. This car has a penchant for eating PS pumps, so i picked one up and put it into the trunk. Personal issues didn't allow me to investigate the actual cause of the noise on Sat/Sun, though. I pull off the road and find that the noise stops at idle, but then the battery light illuminates and the engine dies. The temperature gauge indicates about 1/2, the normal operating temperature is a little over 1/3. This isn't a chevrolet, and has enough reserve to go to 1/2 safely. I observe the water pump pulley is sitting off to the side, smoke/steam is coming from the base of the head, and the three front spark plugs. (this is a push rod engine). Back cylinder head appears fine. I attempt to turn the shaft of the WP, and find that it is seized. I go back into the car, deluding myself about why smoke would be coming from the head, and check the temps. 1/2, which should mean that I would be ok HG wise. Cut to the chase. Firestone puts a combustion gas tester to the resivoir and says that it instantly lights up . Normally, I wouldn't trust firestone for shiat, but their pronouncement combined with the observed smoke probably means that the head gasket is gone. 36-48 hours and a ford pick up truck later, I'm at school waiting for an advisor to add me to a class that I was dropped from for lack of first day attendance.

Here's the details.
These ford tauruses 96-06 seem to have a significant problem with rust in the coolant system. If you go to any junkyard, you would be hard pressed to find a taurus cooling resivoir without rust in it, whereas a ford ranger with the same engine will have a spotless bottle. I was losing about 1 thermostat a year because they were sticking open in this car (due to rust). vehicle gets driven about 25k a year of mostly city driving. Late Last year, I changed the thermostat and completely replaced the antifreeze mix with distilled water, which was changed every 3 months or so. This was in an attempt to get the system clean enough to go back to antifreeze by november. I live in florida, so i didn't need the freeze protection. The car also had almost none of the endemic vulcan ping when it had a fresh charge of distilled, so i knew that some nasties needed to be purged from the cooling system. The coolant bottle had recently become consistently clearer than before. I also changed the front bank (only) of the spark plugs immediately before this happened, but I'm pretty sure that has nothing to do with it....I hope. Also, I had begun to lug this car out a lot more because of gas prices. Not the smartest thing to do in a car with congenital pinging issues, but it was done. by this i mean 37 mph at ~1300-1400 rpm in a 35 or lonely 40mph zone. No milkshake on dipstick.

Alright then. There are a lot of mechanically inclined people here. This motor is not prone to gasket failure. Anyone take a guess as to why it failed?
Was it:

Coolant pump failure (indicated temp didn't get above 1/2)
Clog somewhere/rust
Pinging combined with lugging
Spark plugs (i know)
Old age of gasket and hard life (170k miles/260k km)
Distilled instead of antifreeze

Or some combination of all. Thanks. Also, please don't suggest that I junk this car. I learned to drive on it, and it provides pretty consistent service and very low cost of ownership. I would like to do the HG on it myself.

[bad_manners_god]

As far as your temp gauge goes, you can drive a car with a lot of coolant missing, as long as your going fast enough the incoming rushing air cools the engine.

Happened to me on my E34, driving all day no problem, stop at red lights, stop signs, no sign of over-heating. If you stayed stopped for more than 1-2 minutes the temp would start to creep up and then at the 3/4 mark start to rise fast so I would start driving again and in a couple seconds the temp gauge goes back to the middle.

As far as the reason it could be any of those (except water instead of anti-frezze)....to check if there is a clog, take out the thermostat and put a garden hose through the opening and see if water comes out the other end at a steady pressure....if it doesn't it's a clog somewhere between the thermo housing and the bottom rad hose.

The thing about doing the HG on a V6 is that both could be finished and you wouldn't know unless you opened both heads. So it means doing 2 HG's.

[repenttokyo]

As far as your temp gauge goes, you can drive a car with a lot of coolant missing, as long as your going fast enough the incoming rushing air cools the engine.

Happened to me on my E34, driving all day no problem, stop at red lights, stop signs, no sign of over-heating. If you stayed stopped for more than 1-2 minutes the temp would start to creep up and then at the 3/4 mark start to rise fast so I would start driving again and in a couple seconds the temp gauge goes back to the middle.

really really bad idea on the M50 engine, or any engine with aluminum heads.

[Ross]

Read your own post. You're kidding. Right?

[whiskychaser]

I am amazed Ford US was still making push-rod engines in 1999. Ford UK stopped making them about 30 years earlier when they discovered the over-head cam That said, you mentioned the water pump was seized. That's enough to stuff the motor on its own. Are we looking for more reasons?

[repenttokyo]

I am amazed Ford US was still making push-rod engines in 1999. Ford UK stopped making them about 30 years earlier when they discovered the over-head cam That said, you mentioned the water pump was seized. That's enough to stuff the motor on its own. Are we looking for more reasons?

the corvette still uses a push rod engine, there is nothing wrong with the design.

[whiskychaser]

the corvette still uses a push rod engine, there is nothing wrong with the design.

This has got to be a misunderstanding in terms. A pushrod engine pre-dates engines with overhead cams. Even the M30 has them

Edit: Just re-read your original post. It says SOHC so it clearly isnt a pushrod engine. Either way a stuffed water pump isnt going to keep it cool

[repenttokyo]

This has got to be a misunderstanding in terms. A pushrod engine pre-dates engines with overhead cams. Even the M30 has them

Edit: Just re-read your original post. It says SOHC so it clearly isnt a pushrod engine. Either way a stuffed water pump isnt going to keep it cool

i don't understand...what is so wrong with using a pushrod engine? It is an inexpensive way to make power.

[ryan roopnarine]

pardon ai moi about sohc. my mistake. 12 valves, pushrod. i've had too many fools ask me sohc or c to differentiate between the two and try to sell me fan clutches for this fwd car in the last 48-60 hours that i got confused.

[ryan roopnarine]

I am amazed Ford US was still making push-rod engines in 1999. Ford UK stopped making them about 30 years earlier when they discovered the over-head cam That said, you mentioned the water pump was seized. That's enough to stuff the motor on its own. Are we looking for more reasons?

more like 18-20


http://en.wikipedia.org/wiki/Ford_Cologne_V6_engine