Kaptain

I've done a bunch of searching and the threads always seem to die with no follow ups of the actual problem.

I need to figure out if those 'coolant pass-through' lines would spray coolant throughout the throttle body or just into certain intake manifold ports.

Thanks. I'll need to take a closer look at everything this week and hopefully see the obvious problem.

c0ugar69

thats good, doesnt seem to be a head gasket issue at all, I did see something like this in another thread and it was the gasket for the intake i think.

weaselman

i have always had good luck with felpro gaskets from autozone and rock head gaskets, although after 4500 on my rebuild i sold the truck and havent seen it since, so who knows. lol.

Kaptain

Well I'm not sure what to think now... Did a compression test and I don't see any obvious problems from that.

1 - 165 PSI
2 - 175 PSI
3 - 180 PSI
4 - 175 PSI

This is what surprised me - I opened up the butterfly for the throttle body and I saw a ton of moisture which I'm sure is from the coolant.



This is the best picture that I could get. The worst of it was around this which goes to the PCV valve IIRC (in yellow)




I looked at the intake manifold again and all the ports look really clean but 3 and 4 seemed to be the ones with more signs of coolant... The only thing that comes to mind is the engine\intake is tilted back so anything would 'flow' back to these two...



So... is it the auxillary air valve with a bad seal that is letting coolant into the throttle body? I think that's a reach as I've never heard of anybody actually having this problem?

I happen to have another throttle body laying around... or I could bypass the coolant line going into the intake. I'm not sure what I'm going to try next at this point - gotta think about it.

hnugen

Not the first and wont be the last. The RockAuto headgasket looks like all the Ebay headgaskets I've bought. I bought two sets of Ebay complete gasket kits for the miscellaneous gaskets (much cheaper than buyer a kit or individual pieces from local stores). Why would you not spend the extra $20 for an OEM headgasket? ...or OEM valve seals, NPR rings, OEM rear main seal, OEM timing chain tensioner? It doesnt cost that much more and the peace of mind is priceless. As far as I can tell from visually inspecting the parts in my hand, all the Rock Auto and Engnbldr parts are cheap Chinese or Taiwanese garbage. I've installed them for people and would never use it myself. Flame me all you want, that is my opinion.

Kaptain

I'm all about using OEM quality parts... especially when it comes down to seals, gaskets, and bearings.

When I bought my rebuild kit from EB I didn't think twice about the gaskets - his parts had a very good reputation and they appeared to be high quality.

drew303

I had a ROCK HG fail.... But the ROCK HG on our other yota is something 30k in now doing fine *knock on wood*

replaced mine with an OEM...

Every HG I've seen fail (and I've seen many) its usually from the metal ring around the cylinder not lining up right and protruding into the cylinder.. gets pinched..erodes..fails. Haven't noticed a pattern with any particular brand either just seen this with all makes.

Kaptain

I swapped the aux air valve on the bottom of the throttle body - I didn't see any obvious problems with the old one so I didn't think that would make a difference. It didn't. It's been burning more and more coolant but still not loss in power.

I did another compression test with it warmed up this time... still looks normal.

1 > 178
2 > 170
3 > 178
4 > 178

So I ripped off the intake and it looks like the intake gasket failed at the heater supply port and the coolant made its way to # 3 and # 4.

Kaptain

This part of the gasket was 'bubbled' up so I'd say that's where the coolant started to flow into the intake. The gasket wasn't attached all that well either - it just peeled up.





So it looks like the headgasket help up after all - any thoughts?

And yes, I'm lazy... I really didn't feel like pulling the head.

Lumpy

I've had some odd issues as well. I have done 3 HG's in as many years...

1. from the P/O and a bad rad. Rock kit from EB
2. head bolts loosened up some and lost it on #3 after 25K. Install Rock HG and new head from EB
3. Just did again, but I'm not sure if it was actually the HG or the intake as you had stated. The intake gasket looked rough but I can't be certain. Installed Felpro this time. So far so good. Need to check bolts this week and adjust valves.


.

Kaptain

Well, it was the headgasket after all.

I see it failing on the exhaust side of # 4 and # 2. The fire ring on # 3 also was starting to look mangled but wasn't leaking yet.

I still don't understand why this happened so soon. One thing I will focus on is keeping the engine running cooler - the clutch fan needs rebuilt which hopefully fixes the gradual temp climb during low speed + high RPM climbs\snow runs.

To do :

- Take head to machine shop
- Toyota Head gasket this time
- Re-use ARP head studs
- Scotch bright and thoroughly clean the block surface
- Check block surface for warpage

Kaptain

Kaptain

I rebuilt the fan clutch while I waiting for the machine shop to finish up the head.

It took 1 bottle of silicone - so it was a bit low (takes 3 bottles when completely empty).



There's more drag on it now when it's cold - it still seems to not be fully-engaging after the motor is warmed up. Wish I had a known working one to compare it to.

OEM Toyota gasket and ARP studs going back in. It's all back together and running better than ever.