Head Gasket Screw Up

onium · Post by **onium** » Tue May 17, 2005 9:38 pm

Hello,

I just got done replacing the head gasket in my '84 with a 3AC and upon start up was greeted with a very unpleasant surprise. Within a minute water/coolant/oil started to shoot out the front left corner between the head and the block.

Obviously I screwed up some where, but my question is if any of you know how that might have been.

Here's what I know:

--I immediately checked the head torque and it was fine.

--I completely scraped the block of any and all remaining gasket material.

--I did not use sealant between the head gasket or block.

--Some oil did get into the water system when I removed the head, which I was going to flush out within a few miles of driving/break in. There may also have been a few bits of old gasket material that got into the water chambers around the cylinders.

--neither the head nor the block were warped.

If anyone has any ideas I'd love to hear them.

Thanks

3A-C Power · Post by **3A-C Power** » Wed May 18, 2005 9:52 am

Defective gasket? If the head and block are both straight and clean and the bolts are torqued, there's nowhere else for stuff to leak.

onium · Post by **onium** » Wed May 18, 2005 1:26 pm

I hope it's just a defective gasket. I know the head was straight because I just bought a reman and the block should be nice and flat since the previous gasket was not leaking (head was off to repair a valve issue). One last tidbit: the install instructions mentioned cleaning all the oil off the reman part before installing. If felt dry, but could a very thin film of oil on either the head or the block have anything to do with this magnitude of failure? Would a sealant of any kind helped here? I'm tearing back into it soon, so will have a direct look in a day or so...

3A-C Power · Post by **3A-C Power** » Wed May 18, 2005 2:25 pm

A bit of oil shouldn't matter. I expect with a leak that bad you will see the cause right away.

clbolt · Post by **clbolt** » Wed May 18, 2005 6:37 pm

onium wrote: I know the head was straight because I just bought a reman

Don't let that give you a false sense of security. The surface could have been damaged in shipping or handling, or the head could be cracked. I've seen some really crappy remans over the years.

As far as using a sealant on the head gasket, for a composite gasket the usual answer is no. There are exceptions, such as using silicone around the oil feed on the original composite head gasket on neons. That problem was eventually fixed with the introduction of the MLS (all steel) gasket, which requires a coat of Permatex Copper gasket spray.

I've used that same copper spray on exhaust gaskets so I could reuse them, but I've never tried it on a conventional head gasket.

onium · Post by **onium** » Thu May 19, 2005 11:51 am

I would hope they had it straight as the place seemed reputable and it came with a 12month warranty for what that's worth. Who knows and I agree that remans can suck pretty badly.

One more thing to add here which will expose my newbiness for what it is and may have cost me a couple hundred bucks. I realize now that I didn't prime the cooling system. I'm not even sure how to do this, but imagine that pouring a little coolant down the radiator pipe leading into the head would have helped a lot here. However, I had it running for less than a minute and the head only felt warm when I was cleaning up the mess -- could this have lead to the warpage? I have a bad feeling the answer is yes...

thanks for the info so far.

onium · Post by **onium** » Thu May 19, 2005 4:58 pm

I think I figured it out.

Called the people I bought the head from and asked about priming the cooling system. This is something I should have done before starting up, but alas, I didn't. Failing to prime leavs a big air pocket in the head the has to get purged when the thermostat opens. Seems to me that it would get burped out either the top radiator pipe or the heater hose, but I guess not. Instead, it burped out the front of the engine and blew the head gasket. Damn. :wacko:

I guess I know what I'm doing this weekend.

--

GTSSportCoupe · Post by **GTSSportCoupe** » Thu May 19, 2005 5:31 pm

onium wrote: I think I figured it out.

Called the people I bought the head from and asked about priming the cooling system. This is something I should have done before starting up, but alas, I didn't. Failing to prime leavs a big air pocket in the head the has to get purged when the thermostat opens. Seems to me that it would get burped out either the top radiator pipe or the heater hose, but I guess not. Instead, it burped out the front of the engine and blew the head gasket. Damn. :wacko:

I guess I know what I'm doing this weekend.

--

Doh!!

Sorry to hear that. I've actually never primed any engine that I've done a head job on, I'll have to keep that in mind. Guess I've been lucky so far.

clbolt · Post by **clbolt** » Thu May 19, 2005 7:13 pm

Renaults used to come with a screw valve in the upper radiator hose that was used to bleed the air from the cooling system when you refilled it. I used one or two on other cars, they were nice little brass valves that could be installed in any radiator hose.

BTW, if you want to talk about a car with a difficult cooling system to bleed, try owning a Fiero. I had one given to me once by a guy who was convinced it had a bad head gasket. A new thermostat, both caps, 2 gallons of coolant, and a couple hours burping the system earned me a nice driveable car.

onium · Post by **onium** » Thu May 19, 2005 10:50 pm

doh is right. I guess that's why the instructions state in bold that "failure to prime the system will result in damage". I'm kinda surprised that it would though considering the relatively low pressure a water pump can crank out compared to engine compression... Funny thing is, none of the repair manuals I've looked at mention this anywhere. I guess it comes with mechanics' experience? Hopefully the head is okay and I can get my tercel running again. Love this car and don't want to part ways too soon.

Gasoline Fumes · Post by **Gasoline Fumes** » Thu May 19, 2005 11:48 pm

I've never heard of priming a cooling system. <_<
I always just let the air work its own way out with the cap off when changing coolant (unless there's a bleed valve). Is it any different when changing the head gasket? I'm about to do a head gasket. :unsure:

clbolt · Post by **clbolt** » Fri May 20, 2005 12:20 am

"Prime" is a strange word for them to use in this instance. I've heard it referred to a bleeding or burping the system, but never priming. The damage that can be caused by having air in the system has nothing to do with the pressure put out by the water pump, it's a matter of not cooling the engine. If you airlock the cooling system, not only are the areas filled with air not cooling, but coolant isn't circulating through the system. Overheating results, and a blown head gasket or cracked head can result.

If the damage occurred within a minute of initial start-up, I suspect airlock had nothing to do with it. I could be wrong, but it sounds like something else was wrong.

takza · Post by **takza** » Fri May 20, 2005 3:30 am

I just flushed the cooling system in my wagon for the second time and this involves at least draining the radiator and I assume the head, before the flush itself.

I always run the car up to normal temp by idling it with the cap off to be sure it is full...before closing it up and driving it. No problems.

As far as the head and engine block...find a good straight edge and check with a feeler gauge for true? Not too sure where a really accurate straight edge could be found.

Someone was also talking about oil leaking from the head gasket area...seems I might have this issue towrads the front...can't say for sure...don't think it is the valve cover gasket...it's new and the oil seems to start at the head gasket...first time I've noticed this with an engine that I can remember...could be from the AC compressor.

onium · Post by **onium** » Fri May 20, 2005 10:40 am

yeah, I've got a bad feeling the sequence went something like:

--engine start idle, idle, idle with no coolant in the head
--engine gets warm enough to open thermostat, but by then the head is kinda hot
--water/coolant contacts hot head, flashes to steam and looks for a way out
--maybe head was hot enough to warp
--either way, steam/water/oil bursts out the front in a fantastic, slimy spray
--once proud driver begins cursing and shuts engine off promptly.
--feeling of dread envelops.

Thanks for your help here. Should have gone here first for advice.

3A-C Power · Post by **3A-C Power** » Fri May 20, 2005 11:28 am

I didn't prime the cooling system on either of the heads I've done and numerous times draining and filling cooling systems. No blown engines so far. I could be lucky.