Westly7

so this is my second thread follow up from the first one
92 pickup 2wd 5speed with 22re 160k mileage
i've been blowing some rad hoses and loosing coolant and yesterday idle starts surging from 1100-2000 ,temp always normal below half.
i searched the similar symptom found some answers like broken TC guide or blown headgasket
this morning i opened the valve cover and found out this
no milkshake inside the head
TC guide still there and looks new







so i guess its not the TC guide.
any other possibility?
does this have something to do with my idle surging?
im prolly gonna run to autozone to borrow cylinder compression test to see if its the HG
any input will be appreciated.thanks

SPARKS89

iTrader: (1)

You may have an air bubble in your coolant lines now. That could affect your air bypass valve on the under side of your throttle body. The purpose of the valve is to allow more air into the intake on a cold start, but as the coolant/engine warms up it closes the valve which reduces the idle speed as the engine warms up.

Make sure you've repaired the coolant leak and burp the system real good. I think you have an air pocket that's not letting coolant get to that valve.

ZUK

iTrader: (1)

blowing hoses sounds like a headgasket issue....and not having the milkshake still means it could be the HG. Checking the psi of each cylinder might tell a story.

Westly7

Spark: could it be that valve is failed? The car starts fine n idles great till reach almost normal temperature and starts surging from 1500-2000 (high idle)
ZUK: i heard that but i let the car idling for awhile and temp never get hot,will the idle surging parts of HG symptom?

ZUK

iTrader: (1)

I think it's possible to have a surge with a HG that is blowing some pressure into the water jacket....and might also leak some coolant into the combustion chamber. A clue to which cylinder is leaking is to remove the spark plugs and see which one is squeaky clean. I had a Sami with a blown HD and the upper radiator hose was under great strain due to the chamber air entering the coolant system. The pressurization of the hose seemed random but when it did happen it blew large amounts of green stuff out the overflow and on the road....does yours blow it out the overflow?

ZUK

iTrader: (1)

Thinking as to what would likely cause the HG to fail in the first place?....did you recently have an overheating issue where the gauge touched the red? Bad radiator or fan clutch? Broken waterpump belt? That would cause the HG to stress...and lead to this air leak.

ps----I just read your other thread and the air bubbles in the water say it all....you need a new HG.

Westly7

Removed spark plugs and cylinder #1 is full of carbon black and 234 are clean
I did see overflow on coolant once after i drove the car
Man if its HG im so screwed

SPARKS89

iTrader: (1)

Seems a lot of people are saying it's a head gasket issue. I've never had one go bad so I wouldn't know what the different symptoms are. I was thinking it had something to do with the air bypass valve and wondered if that could affect what the ECU was telling the cold start injector it should be doing. I'm interested to see what you find out.

Westly7

YEAH!!!
Spark you were right i opened the TB to take apart tps and iavc and found out there was chunk piece of rubber hose from thermostat bypass valve that blocked coolant flow thru the iavc,i cleaned everything and blow some high pressure air thru everything and put back on..viola idles perfect no overheat no surging thank God

SPARKS89

iTrader: (1)

Glad to hear it! Nice fix!

Philbert

iTrader: (2)

That's great news - good work YT

Did you replace the offending hose as well? Might as well while you're in there and it's throwing chunks of itself into your cooling system....