Who's done headgaskets in Mark8 ?

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russ jerome

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Multiple fills/bleeds thru crossover, spews coolant from vent if started cold with vent removed....headgasket time
Im assuming. Builds up 15psi running, firing on all holes
but creeps up towards the hot area before I back off.

My Alldata tech CD lists 23hrs that includes R/R motor.
I know its tight in there but if Im pulling the motor on
a 175k mile car Im gonna go thru the motor as well.

Anybody one here do there own work? Im an ASE Master
in both heavy truck and auto so Im up for it if it can be
done in vehicle.If she is coming out I have an excuse to
upgrade the rods and crank ;)
 
I've got a 98 and I replaced the head gasket several times with the motor in the car. It is possible but no fun at all. I only have done the passenger side which is the easier one. Bolts must be zip tied or rubber banded in the head as you place it on the block due to no room after the head is in place. Have fun.
 
Don't....


Just go buy a low mile motor and doing an R@R.... 8-10 hour job.... no timing chain BS.....
 
kustomizingkid said:
Don't....


Just go buy a low mile motor and doing an R@R.... 8-10 hour job.... no timing chain BS.....
Click to expand...

I tend to agree with KK. If your on a tight buget though it can be done in car. You being a tech which i'm not the chains won't be an issue. I never had an issue with it. Just watch how the cams move when the other crank chain is releast. And mark the chain-gears. you'll be fine.
 
I just feel like it's too easy to screw up the timing.... and motors are cheap cheap now with how old the cars are.
 
I've done triton heads (ejected plugs) so Im familiar with
the chain/tentioners Ford uses as well as the rubber band
trick required on many other makes.

So I guess the question is will the drivers side head come
out knowing the passenger side will??

I havent seen any "cheap" 4.6 DOHC around here but I will
cruise a buddies salvage yard if for no other reason to see
if I can find the better heads you guys talk about. If I do
pull the motor I'll build the lower for one of the many used
turbos I have in my garage.
 
I was walking in a yard in Dallas that I was tripping over Mark VIII motors... but up here in the norther parts of the world they are a bit harder to find. Just remember that you can use any long block 93-98....
 
I set off to strip the motor today but figured I would give
it one more test. The rad to t-stat hose is not getting much
more than warm as the upper's read *195 +/-, scanner
reads up to *210 before I shut it down. Radiator cool and
motor hot.

Put in a T-stat just to see if its blocking my flow as the fan
is not cycling (fan does work eventualy but only after heat
soak, not at desired threshold). Same issue may throw a
water pump on as Im gonna do it anyway when tore down.
I'll research but Im guessing the fan switch reads of rad
and not engine sender.
 
If you drained the coolant you may need to fill from th etop heater core line at th eback pass side of the engine bay. I cann't open my cap on the cross over pipe so thats how I get it filled. It will take a lot in that way if it was drained and not filled right. I'm just throwing this out there. Sounds like the same thing that happened the first time I drained the coolant.
 
I don't think you are burping it properly mang... I just had to show Mafioso how to do it and he was battling all sorts of cooling issues before I did....

1. Fill the system at the cross over cap with the resevoir cap off
2. Put the resivoir cap on when it gets to the full mark and continue filling at the cross over cap
3. Get a funnel that fit tightly in the crossover and fill it with coolant so that it is about half full
4. Start the engine and let it idle while you squeeze the hoses
5. Shut it down and let it sit for about 30 min
6. Restart and let it run again and warm up and get more air out
7. let it cool and then take almost all the coolant out of the funnel
8. Put the cross over cap back on
 
kustomizingkid said:
I don't think you are burping it properly mang... I just had to show Mafioso how to do it and he was battling all sorts of cooling issues before I did....

1. Fill the system at the cross over cap with the resevoir cap off
2. Put the resivoir cap on when it gets to the full mark and continue filling at the cross over cap
3. Get a funnel that fit tightly in the crossover and fill it with coolant so that it is about half full
4. Start the engine and let it idle while you squeeze the hoses
5. Shut it down and let it sit for about 30 min
6. Restart and let it run again and warm up and get more air out
7. let it cool and then take almost all the coolant out of the funnel
8. Put the cross over cap back on
Click to expand...

+1
the funnel is a huge time saver and really works!
 
you should do a test to check for combustion gases in the cooling system.
If none are present then KK is right and you haven't gotten all the air out of the system.

Putting the front up on ramps, and using a funnel as described above really helps.

then on the following day, open/loosen the crossover cap.
If coolant starts to come out, tighten it back up
If no coolant comes out, remove and top it off with the engine not running

2-3 subsequent checks will ensure you have gotten ALL the air out of the system
 
htrdlincoln98 said:
Yes this is a great way to do this IF the cap comes off..
Click to expand...

if you cant get the cap off..most of the time it will come off if you are determined and crafty.

i had one, I couldn't get the cap out of.. it was very rusty and corroded.
I just replaced the crossover tube..got a nice one from a salvage yard for 10.00
 
I've been reading your guys' posts for several days on the
subject before asking :) I have a funnel and extention
housing that stands a foot above the motor ;)

I also welded a grab handle to my crossover plug, after
20 bleeds I got tired of using a quarter inch wrench!

Its been sitting since last evening, going out again to try
until a buddy comes by with some dye to check hydrocarb
in coolant.

I read up on the fan as well, it should have come on last
evening (it did work the day before during overheat) as
it uses the upper crossover sensor in my 97.

The coolant system in these cars is the worst I have worked
with in 27 years of wrenching, makes the GM reverse flow
system look great.....yuk.
 
kustomizingkid said:
I could get that cap out... no problem...
Click to expand...

I am very glad yours came out. The heater core tube will always come off. My cap on the cross over tube will not come off. I'm sure plenty of other mark owners are in the same boat as me. Mine is a 98 they don't get any newer!
 
Speaking of that pesky plug on the crossover, I put a new O-ring on today. If yours leaks just a little its gonna draw in air overnight as the system goes into a vac looking for coolant, easier to draw in air than anything liquid.
 
htrdlincoln98 said:
I am very glad yours came out. The heater core tube will always come off. My cap on the cross over tube will not come off. I'm sure plenty of other mark owners are in the same boat as me. Mine is a 98 they don't get any newer!
Click to expand...

same here, I drilled and tapped (magnet to catch any metal) the so-called removable cap and threaded in an allen-head screw so I could drain and refiill my 96. cost nothing, worked like a charm.
 
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