Vanning.com logo
Boxdin
Site Navigation


Advertisements
Recent Posts
Which brake rotors?
by frscke1. April 21st 2019 10:49 pm
1975 Chevy G10 Chrome Bumpers??????
by kursed. April 21st 2019 10:14 pm
Utah Van on Hagerty - Barn Find
by Starlord. April 21st 2019 8:31 pm
Just found Original 1976 G10
by RoboforcerX2000. April 21st 2019 7:56 pm
Robo's Lowrider Boogie Van
by RoboforcerX2000. April 21st 2019 7:34 pm
Dr. Bob's Jokes Thread
by Dyno_Dave. April 21st 2019 7:18 pm
Perfect short door for side of chevy van
by JNPerformance. April 21st 2019 2:30 pm
93 G20 wiper motor compatibility
by Lionvan. April 21st 2019 11:50 am
Looking for info on this grille set up??
by Lionvan. April 21st 2019 11:45 am
Chevy Doghouse Differences
by kursed. April 21st 2019 9:26 am
Featured Links
Vanning.Com is a an authorized Amsoil Dealer


Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 3 1 2 3
Re: blown head gasket :eek: [Re: shaggy] #745918
March 04th 2019 10:33 am
March 04th 2019 10:33 am
Joined: Feb 2019
Posts: 29
Lawrence, KS USA
M
Marcela Offline
newbie
Marcela  Offline
newbie
M
Joined: Feb 2019
Posts: 29
Lawrence, KS USA
If you do a pressure test on the cooling system and it shows losing pressure, do a leak down test on the cylinders and it will show you which one or if they are all good, then it is the manifold or some other source.

Re: blown head gasket :eek: [Re: shaggy] #745919
March 04th 2019 12:05 pm
March 04th 2019 12:05 pm
Joined: Sep 2005
Posts: 8,706
Georgia, USA
CatFish Offline
carpal tunnel
CatFish  Offline
carpal tunnel
Joined: Sep 2005
Posts: 8,706
Georgia, USA
Originally Posted by shaggy
"To do leanbh" . You speak Irish Catfish? smile


Naw. But my grandfather did. And his father, and his father, ...... smile


“A van may be safe in the garage, but that's not what vans are for.”

Re: blown head gasket :eek: [Re: shaggy] #747162
April 09th 2019 3:22 pm
April 09th 2019 3:22 pm
Joined: Apr 2004
Posts: 1,744
Ireland
shaggy Offline OP
veteran
shaggy  Offline OP
veteran
Joined: Apr 2004
Posts: 1,744
Ireland
I did a compression test and all cylinders seem good. Gonna do a pressure test on the cooling system and a leak down test and see if I can pinpoint where the issue is.


79 chevy G30 cobra camper conversion.
[Linked Image]
Re: blown head gasket :eek: [Re: shaggy] #747165
April 09th 2019 5:51 pm
April 09th 2019 5:51 pm
Joined: Jun 2010
Posts: 14,166
Van Diego California
frscke1 Offline
frscke1  Offline

Joined: Jun 2010
Posts: 14,166
Van Diego California
Heater core ....


SUNSHINE VANS-VAN DIEGO
ADRENALIN BY THE GALLON & CHASIN RACIN
ONE FOR THE DIRT & ONE FOR THE STREETS
'93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB
'92 CHEVY G30 454 BEAUVILLE EXT 146" WB
Re: blown head gasket :eek: [Re: shaggy] #747194
April 10th 2019 4:36 am
April 10th 2019 4:36 am
Joined: Apr 2004
Posts: 1,744
Ireland
shaggy Offline OP
veteran
shaggy  Offline OP
veteran
Joined: Apr 2004
Posts: 1,744
Ireland
Yeah that's what I was thinking frscke1. If I bypass the heater core by just connecting the hot-in and cold-out water lines back to back and refill the radiator overflow bottle then I can see if the level drops over time and that should tell me.
I have a feeling I ran it like that before though and was still losing coolant.


79 chevy G30 cobra camper conversion.
[Linked Image]
Re: blown head gasket :eek: [Re: shaggy] #747252
April 11th 2019 11:39 am
April 11th 2019 11:39 am
Joined: Apr 2004
Posts: 1,744
Ireland
shaggy Offline OP
veteran
shaggy  Offline OP
veteran
Joined: Apr 2004
Posts: 1,744
Ireland
So ... the heater is disconnected /bypassed so it can't be a leaky heater core. I guess that means inlet manifold is the most likely culprit.


79 chevy G30 cobra camper conversion.
[Linked Image]
Re: blown head gasket :eek: [Re: shaggy] #747306
April 13th 2019 12:07 pm
April 13th 2019 12:07 pm
Joined: Mar 2019
Posts: 6
Riverdale, new jersey, united ...
J
Juntao_DW Offline
stranger
Juntao_DW  Offline
stranger
J
Joined: Mar 2019
Posts: 6
Riverdale, new jersey, united ...
Lilse tools makes a kit 75500 which is an exhaust tester for the cooling system so if its impossible to do a cylinder leak down test its always another option to help determine if you do have compression loss into the cooling system.

Re: blown head gasket :eek: [Re: shaggy] #747307
April 13th 2019 2:09 pm
April 13th 2019 2:09 pm
Joined: Nov 2013
Posts: 1,138
West Texas
W
Wedgy Offline
old hand
Wedgy  Offline
old hand
W
Joined: Nov 2013
Posts: 1,138
West Texas
Hidee Ho Shaggy,

Long, long ago in a Land far away, a wounded 1969 327 smallblock rebuilt by my FIL, was losing coolant, powering a 1970 Chevy C10 down the road. This was unacceptable on a 90 mile daily commute. Take a quick look into the radiator with the engine running, at operating temperature, radiator cap off. Check for exhaust entering the coolant. It will be readily apparent. Have a friend apply throttle, engine in park, parking brake on, safety first. Look for tiny bubbles! If you see them increase when the motor revs up, hate to say, but the heads probably should come off that motor. Mine were still fine, but don't let that motor overheat.

Yes you can reuse intake bolts. Clean all inspect threads well, pay special attention to the proper gasket installation, torque, and don't misalign the intake valley gasket putting the intake on. That Sucks...

Just use proper attention to detail upon reassembly, and you'll be fine, (FIL Leonard at Precision Engine...) grin

Lucky for me, since I knew who rebuilt mine, I brought it up on occasion! The fun part upon reassembly on a Chevy smallblock is hydraulic valve lash adjustment!

Chevy Tip: Take an old pair of steel valve covers, and cut the tops off, bolt them on first, way less smoke that way.

Good Wrenching!

Re: blown head gasket :eek: [Re: shaggy] #747343
April 15th 2019 6:36 am
April 15th 2019 6:36 am
Joined: Apr 2004
Posts: 1,744
Ireland
shaggy Offline OP
veteran
shaggy  Offline OP
veteran
Joined: Apr 2004
Posts: 1,744
Ireland
My thinking is that seeing as I have good compression on all cylinders that doing a leak down test wont tell me anything more.
That said I have a loan of a leak down tester so I may as well use it and see if what it tells me.

There was no sign of water on the plugs and the engine is running well and firing on all cylinders even on start up from cold so I don't think water is getting into the combustion chambers at all.
But I am losing a small amount of water and there is an oil glaze on the coolant when I drain it and a bit of mayonnaise inside the oil filler cap.

My suspicion is that it is a bad seal on the intake manifold gasket around one of the water passages between inlet manifold and one of the cylinder heads and it is weeping down into the valley from there and down into the sump. I'll pull the intake manifold and leave the heads alone, replace the intake manifold gaskets and see if there is any evidence off losing water.

I'll also check for bubbles in the rad as you suggest Wedgy.


79 chevy G30 cobra camper conversion.
[Linked Image]
Re: blown head gasket :eek: [Re: shaggy] #747373
April 16th 2019 2:08 am
April 16th 2019 2:08 am
Joined: Apr 2010
Posts: 2,665
San Diego
W
wrcsixeight Offline
veteran
wrcsixeight  Offline
veteran
W
Joined: Apr 2010
Posts: 2,665
San Diego
Mayo on the oil cap could just be short trip driving in cool weather.

O once did an used oil analysis and they indicated Sodium and Potasium, indicating coolant in the oil, and as I suspected the timing chain cover and water pump bolts were allowing coolant past their threads.

Some 8 years ago I got a new all Almuinum radiator, 9 months later it was seeping coolant from teh seam where the tubes met the bottom tank. I used some of the Gm coolant fitness tabs, at 1/6th the recommeded dosage and the leak stopped. Same radiator now 9 years later. If i drain teh coolant and refill it without the Ginger root Gm coolant fitness tabs, it wll start weeping at the same exact spots. It never dripped, and was a very slow loss of coolant and if it were a black painted copper brass raditor I might not have noticed where it had been slowly weeping coolant.

My heater core is not delivering the same heat it used to though, perhaps that gibgerroot stop leak bars leaks tabs partially plugged it. perhaps the blend door insulation is shot, perhaps both. I plan to backflush it at some point. it stil gets warm, but 22f at 7K feet and 65mph this previous November, it was not effective.

So I would say to very closely inspect the radiator where the tubes and fins meet the top and bottom,or side tanks, for signs of weeping.

A radiator which does not weep would certainly be better, but I am on year 8 or 9 of the same radiator which weeped at 9 months, thanks to this specific product's efficacy.

[Linked Image]

Lot easier and cheaper than pulling the intake manifold, and if no change, well you will be changing at least a portion of coolant when you do the intake anyway. If GM still sells products in Ireland, Gm relabels this specific prduct and calls them Gm coolant fitness tabs. My landlord is a service advisor at a busy respected auto repair joint, and says most ethelyene glycol coolant using vehicles that have cooling system work done on them go out with a few of these in there to prevent comebacks.

Page 2 of 3 1 2 3

Moderated by  Astro 

Donate


Upcoming Events
discovery
Who's Online Now
1 registered members (1 invisible), 3 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Newest Members
73ChevyShorty, Vanner37, DURFMEYER, boogieG10, joescout
10863 Registered Users
Top Posters(30 Days)
frscke1 73
Wedgy 46
Reed 31
kursed 25
Forum Statistics
Forums68
Topics35,657
Posts519,118
Members10,864
Most Online177
May 8th, 2013

Powered by UBB.threads™ PHP Forum Software 7.6.1.1