Little red pickup

[sgnimj96]

Dang.
A sobering reminder that the universe is not static.
I'm looking forward to learning something about this. There are a few internet discussions about this type of issue,
but are brief and don't explain much - a veil of the automotive occult.
Thanks for drinking of that cup, EH

[Fatmobile]

I've seen something similar when the small line to the reservoir is blocked.
It traps air in the head because it can't get to the high point of the reservoir.
Probably why I'm thinking that way this time.

[Fatmobile]

Maybe all head gaskets aren't created equal.

Here's a link to the last head gasket I used:
https://www.rockauto.com/en/moreinfo.ph ... 12&jsn=452
It's made by Ajusa.

Here's one made by fel pro:
https://www.rockauto.com/en/moreinfo.ph ... 12&jsn=448
Look at the coolant passages near the 4th cylinder on both of the gaskets.

They are way larger on the fel pro gasket.

I've been going over this in my head.
Trying to figure out why the 4th cylinder isn't getting the heat carried away.
If it's not a problem with the head the only other thing I can think of
is maybe something in the block is coming up and blocking the coolant holes in the gasket when it's running.
Unlikely I know but possible I suppose.
So I ordered a couple fel pro gaskets. Cheap on clearance right now for about $16. Plus shipping puts one at about $24
I still need to figure out a boroscope to buy so I can look inside the head passageways and compare them to another head.

[sgnimj96]

I used this one,
https://hansautoparts.com/068103383FMHeadGasket.aspx
+ hylomar spray. ARP's re-torqued 2 or 3 times
Maybe that cheap gasket squeezed down to a 1ntch, but it's working

Those felpro ones are nice, but when I needed one they were out.
2-notch gaskets are hard to find for some reason.

[Fatmobile]

Lot's of people slam hans's parts but I've bought stuff from him before that was good.
The holes around the 4th cylinder on that gasket are small too.
So far the Felpro gasket is the only one I've seen with big coolant holes near the 3rd and forth cylinders.

I've noticed the 2-notch shortage also,.. so I bought 2.
Hopefully this is the last one this engine will need.
I still plan to figure out how to lap the valves and put a different head on,..
and get or borrow a boroscope

[sgnimj96]

just glad there is a vendor that still keeps warehouse space for vw parts that others don't bother to stock anymore.
Being ONLY vw helps keep those parts on the shelves, and using oem part numbers makes HANS a go to site
for part searches even if it's only for reference.

[Fatmobile]

I just bought 3 red speedometer cable gears from Hans.
For the couple ACN tranys I've collected
I stuck one in the Rabbit but have no speedometer.

The more I think about it the more sense it makes that the #4 cylinder would be the one to get hot.
It's the last place in the engine for the water to go through.
It starts at the waterpump and travels up and over
then exits at the end of the head and between 3 and 4.

Makes sense for Felpro to make the coolant holes on
that end larger.
To get more of the block coolant there
instead of the coolant that has passed through the head and around the exhaust ports.
Some of that head coolant has already passed cylinder 1, 2 and 3
exhaust, combustion heat soaked.
The incoming air would help to cool it some.

So I like the way they made the felpro head gasket.
I think it's an improvement over others and I might start enlarging the holes on other gaskets.
I ordered 3, 2-notchers because they were cheap
and I really like them,..
golden color with blue bead around it,..
the big front oil drain has an o-ring around it.

But I would never buy felpro exhaust gaskets.
Screen sandwiched between paper? Junk.

[sgnimj96]

Well it's an interesting point. Fel-pro clearly has put some thought into this
"An improperly sized or placed hole can create a shortcut which prevents coolant from following the correct path through the engine. If the coolant takes a shortcut because a coolant hole is too large at the front of the engine, the rear cylinders can overheat. If the holes are properly placed, but too large, the coolant can pass through the engine too quickly and fail to absorb enough heat, also resulting in overheating. "
https://www.felpro.com/technical/tecblo ... skets.html

I do think the cooling system design, overall, should be better than it is. In summer traffic, I find myself turning on the radiation fan manually at stoplights instead of waiting for it to kick on after 200 deg.

Carmakers are always holding back something.
You'd think after all these years of never-ending complexity, they'd make cars with standard features like an indicator for when a tail light is out .
That flow differential may be why the old 1.5's and 1.6's have always had a tendency to blow when they get hot.
I'll keep this in mind next time I do a HG,
Thanks for thinking (while it's still legal) lol?

[Fatmobile]

Got the head off.
Everything looks fine.
I stuck a little LED on a wire in the coolant passages to see where it shines,
compared to a good head.
I'm still going to see if my buddy has an endoscope that's thin enough.

Then I'm going to put this head back on,
with the felpro gasket
and this time I'm not going to tighten the reservoir cap down.
Maybe this will allow some of the air in the head to escape without
over pressurizing the coolant.
Once the air is purged maybe it won't burst into steam in that area.

[sgnimj96]

It sucks that early vw diesels have such a minimal cooling system for as hard as they work.
Bigger stock radiators would have added a lot to their reliavility

[Fatmobile]

Got it all back together.
Put some used antifreeze in it because of the cold weather coming,..
and I don't think water in the block is good for it,
might cause corrosion.

Started it up and it was still missing on one cylinder,..
for awhile. I really hated that truck for awhile but it smoothed out.
I drove it around the block with the reservoir cap loose checked it.
Drove around again, checked.
Did this about 6 times.
All went well. Took a little farther trip out of town, still good.

Tightened the reservoir cap down and went around the block, plus a little farther.
Got back loosened the cap and the reservoir bubbled over bad.
One way to get the oil out of the reservoir, ha
The engine started the boiling sound in the head.

I let it cool and settle down,.. then installed a different reservoir cap.
Tightened it down and went for a ride around the block/check rinse repeat no problem.
Went outside of town and picked up some eggs, checked it.
Got home, checked it by loosening the cap and listening to the head,.. no problem.

Could it have been the reservoir cap all the time?
Blew the original head gasket, caused his heater core to leak and blew every head gasket after that?
I kept thinking the pressure can't be too high or the reservoir release would let go and spill a bunch out the top.
What pressure is it supposed to be?
Starts and runs really well.
Hard to believe it can go from fine to boiling over in just a trip around the block
just because the reservoir pressure release valve is stuck.

[sgnimj96]

Wonky thermostats and/or thermo-switches have cause a lot of watercooleds to lose their heads.
The radio shack temp gauge in the dash doesn't help much for early warning.
Maybe a sacrificed reservoir with a tire valve epoxied into it would be the next-level shop equipment.
Bicycle pump for the official vw rad cap bench tester
It would be cool to know the actual pressure of those caps

[Fatmobile]

It never overheated.
The temp gauge sat perfect in the center.
The whole time it was overpressure.

I didn't take it into town today.
A couple more trips out of town a ways and back
before I try that.

[Fatmobile]

OOps I stuck this post in the wrong thread.

It is having a problem on cold startup.
It stumbles and puts out the white smoke.
After starting it I need to rev it some to get it to smooth out.
Then it runs great.

So I checked the timing with the pulse detector
and it was a little retarded so I advanced it a little.
waited for the next day to try a cold start.

It was better especially with the cold start pulled out.

So I checked the glow plugs.
Pretty sure I put new bosch duraterms in it but I suppose one could go bad.
I use an ammeter bolted into the middle of a fat wire with battery clip on one end
and alligator clip on the other.
Clipped it to the battery and grabbed the glow plug buss.
After about 10 seconds it said it was only pulling enough power for 3 glow plugs.
I have 4 lines painted on the front of the gauge.
I connected it with the glow plug fuse in the circuit,..
pulled plenty of amps, showing the fuse was good.

Still doubting it could be a glow plug so I plugged the block heater in.
It's colder today than any other cold start.
It jumped right to life and ran great.
Virtually no stumble and very little smoke.

I know it isn't #4 glow plug, tested it.
Hoping it's #3 but will probably be one of the hard ones.

[scrounger]

So the entire time what caused the initial damage was over pressure in the cooling system?