Little red pickup

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sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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 :roll: .
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?
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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
Last edited by sgnimj96 on Sun Oct 24, 2021 11:01 pm, edited 1 time in total.
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
Fatmobile
Global Moderator
Posts: 7474
Joined: Wed Oct 30, 2002 10:28 pm
Location: north central Iowa

Re: Little red pickup

Post by 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.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
sgnimj96
Diesel Freak
Posts: 165
Joined: Thu Feb 20, 2014 2:08 pm

Re: Little red pickup

Post by 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 :lol:
It would be cool to know
81' Scirocco 1.6D (conversion)
86 Golf 1.6D
85' 300TD
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