Head gasket?

GaWd · October 9, 2002

The money pit has recently developed some symptoms that resemble a head gasket leak and I need some help determining whether or not it is the case. Then I need to hear from you people regarding the degree of difficulty to repair it by myself.

Symptoms:

1- Blown out radiator

2- funky idle(intermittent problem, probably not related)

3- excess water/presence of anti-freeze in catch basin(reserve tank)

4- After a moderate/hard drive to warm her up, antifreeze leaking out of the

reserve tank(through the cap)

5- When running at temp, high pressure in the rad, bubbling/frothing

anti-freeze which cycles all the way up and out of the rad. in 5-10

increments.

6- Intake gasket leaking antifreeze

7- Gurgling in the morning from the heater core

She still drives well, has loads of power, no apparent water contamination

in the crankcase.

I have all the tools, but have never done a major engine-in repair job like this, and I've never worked with EFI motors before.

Lastly, how long will she continue to run if it is indeed a headgasket problem?

TIA,

Sam

MarkD · October 9, 2002

As long as you are not getting water in the oil, it will probably run a while without locking up on you.

You will have to watch overheating though. It will pressurize the coolant, blow it all out, and you will overheat without any guage indication(no water on the sensor).

I blew a head gasket on a CRX and could only drive 8-10 miles before the radiator was empty.

I would not recommend the repair for your first DIY effort. If your head is not warped, It can usually be done in 4-6 hours.

Repair cost should be $500-$1000 depending on the condition of head.

GaWd · October 9, 2002

THis is far from my first DIY job. I've just never worked on a car this new, and there's a lot more r&r than any other vehicle I've serviced.

CMNTMXR81 · October 9, 2002

A tell tale symptom of a blown headgasket is your oil. When oil and anti-freeze mix, it looks like a chocolate milkshake.

How long it's driveable before the cooling system is empty depends on the severity of the leak.

Sounds more to me like air is present in the system. It could've been introduced and then the system re-pressurized and sealed itself OR it could continually be sucking in air someway somehow. Either way, cooling systems are only under about 14psi when sealed properly.

It's hard for me to give an accurate timetable on the time it'll take to replace a headgasket. Too many variables.

varmint2506 · October 10, 2002

Im definitely no master mechanic, but generally if you have abnormal flow of pressure or water, it flows both directions. If you are not seeing any water in the cyl., oil, or seeing any water at the tail pipe after it has sat a while, it could be a crack that is opening when the engine heats up. Once you shut down the engine the pressure in the coolant will generally push water back through any leaky points.

I dropped a head gasket on my 89 Chevy a few years back. Mine let go going down the interstate. I had a nice cloud of white smoke following me and a massive loss of power. Of course I pulled over and shut it down. I ended up cracking a head due to non-compression of water when I tried to restart. I took the heads and had them magnafluxed and found that the good side even had a hairline crack in it. The new style 5.7 heads are a lot thinner than they used to be. It does not take much to crack one. I ended up buying a set of re-worked heads from the junkyard. They did a complete valve job on them and put a 90 day warranty for $300.00. (GM gets close to that for an empty single head) I used a good set of FelPro head and intake gaskets. The project took about three evenings of tinkering. All in all, I sunk about $400.00 in the top end. I still drive it most every day. It has over 250,000 miles and still runs strong.

Good Luck

GaWd · October 10, 2002

While the tell-tale sign of a head gasket problem is milkshake oil, it isn't a requirement that it be present for the headgasket to be blown. All the headgasket has to do is open up into the combustion chamber from the coolant side to introduce exhaust gas into the radiator and pressurize.

Onto my compression check...

Ok, finally got the time to run a compression test on all 8 cyls. Here are the results:

1- Plug was gray/brown 150PSI

3- Brown, just a hint of oil 165PSI

5- Gray 150

7- gray and brown 155

2- gray/brown 160

4- Oily, ashy, deposits, 150

6- gray/brown 140

8- Funky fouled** 170

**- not exactly fuel fouled, not exactly oil fouled...odd. Maybe coolant fouled?

These results have me confused. I thought I'd have a much better idea of where the void was in the head gasket, but I don't. #4 and #8 seem likely candidates, but I don't know enough about head gasket problems to know for sure.

Any ideas?

Sam

tblazer503 · October 11, 2002

Gotta ask this, but it almost sounds like a cooling problem(most of it) Have you tried changing out the T-stat and radiator cap and poss. flushing out the system? Should only set you back about $30-40max and may help to eliminate some problems to be able to TS better...

Just my $.02

CMNTMXR81 · October 11, 2002

Well, you're averaging 155psi compression'wise which is well within normal parameters. Without knowing your cam profile though, it's kinda hard to gauge whether it's a high or low when combined with your heads. Even though they may be stock, I don't retain the specs in my little noggin.

It does look however like #6 has a problem. Number 6 is 17.64% lower than your highest (which is the cylinder right next to it) #8 and is 9.67% lower than your overall average. That's a pretty big swing and kinda lends creedence a head gasket on that cylinder. Seeing as though it's the only one that is that low, that could give reason why your oil may not look as bad, milkshake'wise. Only one cylinder contaminating it and if it's a small leak, won't amount too much. Of course, it looks exactly the same going the opposite way on #8. 170psi is also 9.67% higher than the average 155psi. That's a significant increase.

Onto my plug evaluation (and don't take this as gospel please ) as it's difficult to accurately assess them without seeing them.

1) sounds/looks ok

3) running a little rich, possibly the oil's fault. Oil could be coming from a wore out valve stem seal that allows oil into the cylinder when the intake valve opens and allows the a/f charge in.

5) sounds/looks ok

7) sounds/looks ok

2) sounds/looks ok

4) potential misfire due too lack of fuel delivery?? Just a thought. Plug fires, but nothing or only oil to burn which leaves the oily/ashy deposit.

6) sounds/looks ok

8) Hello Nancy. Water/fluid doesn't compress. Therefore it's taking up combustion chamber space which artificially inflates the compression number which explains the 170psi. Also coolant doesn't ignite which could explain your moisture problem on this plug.

I'd say you've got a #6 and #8 problem. You remove those two and everything else seems normal.

GaWd · October 12, 2002

Ya, I'm pretty sure it's between #'s 6 and 8.

Now if I could only get the damnedable head off...

All bolts out. All accessory bolts/nuts/studs removed. THe only thing left is whatever's at the back of the passenger side, and I don't think the AIR tube and the little groundstrap would hold a head on solid.

Sam