bad headgaskets plus boost = ?

[Sundance 6g72]

soo im pretty sure my headgaskets where bad while i was NA. Coolant always looked like hell and i think i had some white smoke going on sometimes.

anyways, while NA, if i beat on the car alot i would find a little coolant had escaped past the radiator cap. Nothing big though. Now with boost.. its a different story. The reserve seems to fill up no matter what (even if i keep it empty.. after a hard run, its full)

so my test went like this. i have a boost leak so i took advantage of it. with the wastegate connected to the turbo compressor outlet, i was limited to about 2-3psi. combine 2-3psi with an empty reserve and full coolant system and you get a relatively stable system. my cap still let a little coolant past but nothing huge and after the run the reserve was almost full but it never overflowed.

now with 5-8psi, its a different story. After a few hard pulls i lose alot of coolant.. sometimes the cap gives and it sprays all over and the reserve is deff full and leaking.

now take this into account, the coolant temp rarely goes above 230. i have a 50/50 mix just about so it should not be boiling over. the theory is that bad headgaskets let air pressure into the coolant system and force my coolant out. my temp gauge proves this too because its always busy moving about from cool to hot.

i have two new MLS headgaskets that i can install and probably should, but ill have to wait until my school papers are done, that will take priority.


does anyone have anything to back this up? or maybe a different idea of whats going on. cant see how i would be wrong though. the amount of coolant blowing out of the system seems to be related to the amount of boost i run.

---------- Post added at 01:02 PM ---------- Previous post was at 12:57 PM ----------

on a side not.. my wastegate was almost half open 100% of the time. adjusted the arm and its better.. i can build boost at part throttle and really nail it at full throttle. its still laggy but i kind of like it. 1st gear dosnt need boost and by the time it gets there i jump into 2nd.. i dont lose much between shifts either so im satisfied. as long as i can get rid of this coolant explosion with boost then ill be good.

[turbovanman²]

Yes, you have bad gaskets, your simply pushing air into the cooling system and it has to go somewhere. If your going to keep driving it, I would put a lower pressure cap on or run as little boost as possible otherwise you can blow your rad, heater core or hose.

[c2xejk]

Have you checked your headbolt torque?

When you replace the headgaskets, have the heads milled for flatness and to clean the mating surfaces...

[Sundance 6g72]

Havnt checked headbolt tq... They are factory bolts, factory headgaskets


Headbolts can be resused right?

I can keep the wastegate open to keep boost at 0.

Ill deff have the heads checked for flatness

[bond_bbs]

Yup, you can reuse our headbolts. Just be prepared to find an allen socket, and short extension. Cannot remember the size.

[Sundance 6g72]

Yeah ive removed heads before... It takes a big allen socket.

What is the head tq sequence? I think brent has a pic of what he does in his thread thst ill check later

---------- Post added at 02:06 PM ---------- Previous post was at 01:58 PM ----------

Got an estamite for checking and milling the heads... $120. I guess thats not bad but im broke. I cant emagine the heads are warped cobsidering the gaskets where bad before i boosted the motor.

[turbovanman²]

[/COLOR]Got an estamite for checking and milling the heads... $120. I guess thats not bad but im broke. I cant emagine the heads are warped cobsidering the gaskets where bad before i boosted the motor.

They might be tad warped but I find they like to get pitted. Cheap insurance to have them milled.

[MC#4]

Sounds like head gaskets to me. My car just blew one a few weeks ago. I hooked my cooling system pressure tester up and it would build up to almost 20psi when running. I'd get the white smoke on acceleration off a stop. My number 1 spark plug was wet too. At this point though, I am assuming head gasket but In reality it could be a cracked head. I'd have the machine shop pressure test your heads for cracks if they don't do it right away with a mill job. If you haven't had the heads redone before, you may consider a fresh valve job and everything. I haven't been following your build very closely so I'm not sure what's been done before.

[87turbodance]

Head bolts take a 10mm hex

[Sundance 6g72]

Sounds like head gaskets to me. My car just blew one a few weeks ago. I hooked my cooling system pressure tester up and it would build up to almost 20psi when running. I'd get the white smoke on acceleration off a stop. My number 1 spark plug was wet too. At this point though, I am assuming head gasket but In reality it could be a cracked head. I'd have the machine shop pressure test your heads for cracks if they don't do it right away with a mill job. If you haven't had the heads redone before, you may consider a fresh valve job and everything. I haven't been following your build very closely so I'm not sure what's been done before.

20psi while idling damn.. i hit 6000rpms with 8psi of boost!!

well heres the deal, i have a set of spare heads.

right now, my current heads have bad valve stem seals OR the guides have dropped. mine should be c clipped so im saying its the seals. Im going to pull these heads, mill them if they arnt flat, re install them with fresh stem seals and mls headgaskets

down the road, my spare heads will be self ported (mainy cleaned up) cammed, new valve, guides, springs, and rev to like 8000rpms.. so i dont want to spend to much time on the current heads.

[turbovanman²]

20psi while idling damn.. i hit 6000rpms with 8psi of boost!!
.

No, no, no, lol, he put a pressure tester on the tested the system at 20 psi.

[Ondonti]

If you can't afford it but can afford gaskets, just clean and reassemble. I have gotten away with it many times, even on a head that pushed massive coolant on big power. Copper Spray. You can always straight edge the head and block to make sure but its probably just the fire ring on the gasket failed. Same thing that probably happened to my Spirit. I ran for 5 years on a bad headgasket until my 2nd 2000 mile trip towing another car. I didn't make it the last 120 miles.

[Sundance 6g72]

You know brent, i might go that route. I already have headgaskers and valve stem seals...

I reallly doubt the heads are warped or need milling done... Ive bounce off the limiter many times but only when na... 147hp at work

[Ondonti]

Doing that surface prep is best practice but when you are broke you would rather fix it again then spend money you didn't need to.

[Sundance 6g72]

I guess ill make my decision when i see whats going on

only thing im worried about is tq sequence and getting it right

[Sundance 6g72]

yeah thats what i meant. my bad

heads are off. the front headgasket looked fine. the rear one came off WAY TO Easily.. i just pulled it off the head as if it had copper spray on it.

cyl 5 looks questionable (it looks fine but has signs of coolant being in it?)

rear headgasket had some damage on the edge but not that would allow coolant into the cyl? ill have to check the corner of it.. ill bet money its right next to cyl 5

have to wait till monday im pretty sure in order to get a nice valve spring compressor so i can take care of valve stem seals while the heads are off.

[Sundance 6g72]

so once the heads are Torqued to 90ft lbs, back off a 1/4 turn and then go back to 90?

do i run the motor and then re tq the heads?

[Ondonti]

No, you retorque right away. Do you have the chart for order? I believe i posted that at some point.

The purpose of the steps is to clamp the head down evenly. The purpose for backing off 1/4 turn and going 90 is that your actual bolt clamp loads will not be as consistent when you make small steps. Ever had a bolt not turn but your wrench click? This means you didn't achieve torque properly. At work we are required to reach final torque while the nut or bolt is turning. You get the head perfectly clamped down then back off one at a time 1/4 turn and back to 90 while all the other bolts are tight holding the head down.
If you don't want to go all the way to 90 and don't want to back off 1/4 turn, you still need to do that if on your final step the wrench clicks without anything turning. If it fails to move, you need to back off and then go to final torque (but you don't need to do steps if all your other bolts are fully torqued).

This is the proper way to do it but that doesn't mean I have not gotten away with just 80 pounds and no fancy stuff. This is meant for the MLS headgasket but I used this technique on the Felpro.

I have never retorqued a headgasket. ARP studs or the base quality often need it because they stretch (crap).

[Sundance 6g72]

So 90 is safe for re using headbolts?

I get it now. So i dont loosen all the bolts in order... I loosen and re tq each bolt one at a time?

My order is in my manual at home

[bond_bbs]

The order, which is off the top of my head goes like this if I remember correctly: this is while looking AT the head

(5)(1)(4)(8)
(6)(2)(3)(7)

As said - I'm going from memory, but I think that's the order the Haynes shows.