New HP TD Build Ponderings

[myke_w]

Hey Guys,
I finally put my Jetta coupe build on the road and I have an interesting observation to share.

First a bit about the car. 100% fresh 1.6 hydraulic motor, metal HG with arp studs torqued to 100lb, giles pump, FMIC, new DNS0293 nozzles, boost + egt gauges (of course).

After driving around and taking it relatively easy on the new motor for a few weeks, today I decided to start ramping up the boost and giving her a little hell..

I set my boost controller to open at about 15lbs and took a couple drives.
I only did one full blast run up to 15+ lbs and eased off right away. (It absolutely screams btw )
At one point I noticed the coolant gauge reading a bit hot, not climbing but just laying right of center. I drove around until it read normal and got her back into the stable and popped the hood, and noticed that the upper hose appeared at one point to be leaking at the radiator, also noticed a bit of coolant seeping around the front of the head gasket.   My instincts tell me that I've either already lifted the HG or I'm coming close.  I never got EGT's high and never really got boost high enough that I thought I was in any danger.  Hoses & clamps, etc. everything is new.

I'm just soliciting advice at this point..
What should I do? My instincts tell me I should re torque or add torque.. does that make sense or is it over and time to pull the head? If not - should I just turn the boost controller down? I build run of the mill bone stock diesels all the time but the HP stuff is pretty new to me in practice. Any comments are appreciated.

[carrizog60]

mine also have that coolant leak around the head but only when the engine cools down.
i have a mechanical engine with aaz hg so the problem could be there...

more than 1 year like that and still kicking like the first day. :twisted:

[zukgod1]

I've ran 40psi on my 1.6 Myke with no leaks at the head and at 80lbs on the ARPs.

I do seem to have a slight leak on the upper hose at the radiator, I even switched to a worm style clamp and still there.. Weird.

Anyway I suspect the leak may be coming from somewhere else other than the head gasket but it collecting on or around the gasket?

I'm still breaking in my new rings so I've not gone over 20psi yet, 10-12 first 500 miles.

I'm keeping the fuel turned down right now for reduced smoke and better smileage (I hope).

mine will run the gauge up if I rail on it, I've blamed the FL+MIC from blocking 50% of the air flow to the rad though. Normal driving is fine.
If it's 100+ here and I have the AC going it hangs just to the right of the middle mark on the gauge but I can get it to the third line if I boost it to 15+psi for nay length of time at all.
New radiator, water pump, t stat etc as well.

[myke_w]

mine shows seepage from the front of the head all along the bottom.


I was under the impression that there wasn't a whole lot of risk in running ~15 psi - I thought things started getting unreliable past 20 or so....

Any thoughts?

[zukgod1]

Also this last time I went to 95 on the ARPs instead of the 80 they recommend, with lots of lube.

Oh ya!

I coated the gasket with "Aviation Gasket sealer" this time. I'm not sure why I did but for every other gasket it hold like concrete so I figured I would give it a try.

[myke_w]

I guess I might have to dial the fuel back a bit. LOL!

Ol' Giles had it turned up pretty hot out the door, That crazy fool!!

It'll blow a huge cloud of death if I sink my foot into it for too long.

Also, you and I are in the same boat in terms of flow through the FMIC, being small bumper cars and all, but the funny thing is that EGT's never really go higher than 12 MAX when all this is happening.

I have the hankering to hack out a hole in the valance behind my fmic

I really think we must be close to boiling the coolant (at least local to the head) when we're really flogging it and it can't escape fast enough and expands the upper hose, air comes out of solution.. Hence the gauge going hot and spewing.

I need to recheck the head flange to hose connection, because if others haven't lifted an HG under 20lb I'm fairly confident I didn't. Maybe need to get my old spring clamps back out and pitch the worm gear kind. Might also be time for some water wetter :p

[myke_w]

True dat. It doesn't help that I'm using G12 which is hard to see anyway

I'll go have another good look, methinks my shiny new clamps may be failing me

[zukgod1]

Here is what I did to try to hlp with airflow.

[jackbombay]

My HG on my TDI is now leaking, I have ARP studs in it like you do, I have not read of anyone dealing with leaking HGs with the stock stretch bolts on a TDI. It seems like the ARPs don't keep the head on as well as the stock bolts...

  I'm going to give them an additional 120* in 2 60* incriments and see how that goes...

[Smokey Eddy]

I didnt read the whole thread but sometimes i've had coolant leak from the plastic mounting thing that goes to the head from the top of the radiator. The coolant evaporates (or burns) off the head it's self and settles on the gasket and it appears that the HG leaks coolant but it wasn't, it was the coupling thing between the last two injectors on the right side

[myke_w]

I didnt read the whole thread but sometimes i've had coolant leak from the plastic mounting thing that goes to the head from the top of the radiator. The coolant evaporates (or burns) off the head it's self and settles on the gasket and it appears that the HG leaks coolant but it wasn't, it was the coupling thing between the last two injectors on the right side

Ditto, but my flange is metal - I did confirm that it's leaking from between the hose and clamp. Apparently my clamps are just not beefy enough.
I'm also running a high concentration of coolant to water. I'm gonna back it off and see if I can't improve my heat absorption / dissipation. Maybe time to get some water wetter in there