Heater Hoses Mess..cry for help from the Uk

[UkMark]

Guys..68 gmc
heater is bypassed and the truck permanently runs with the old dash temp light glimmering..no thermostat inside right now which does not help, but the coolent are pumping round quickly enough.
the top hose on the manifold has been put back into the rad[rather than the heater], but i am thinking this is causing issues, i intend to sort the heater matix rad out and re-connect[i need a heater!], but the waterpump doesnt seem to have a bottom left plug to connect the other heater hose back into it..
the truck hasa 72 bed on it, and i assume the engine is not 68 either, some advise would be much appreciated.

[jjzepplin]

Looks like the one that goes to the radiator was going to the heater core and the heater core back to the manifold. When the core failed they just ran the long hose back to the radiator.
If your core is no good then just plug both ends of the long hose going to your radiator.

[Grumpy old man]

You have to have a thermostat or a restrictor plate in the top thermostat housing "the coolant running around quickly enough " and the "old dash light glimmering " are NOT GOOD ! You will never get it to run cool without a radiator cowl in place You will burn up the engine ,Warp valves and blow head gaskets (If your lucky that's all that happens ) Find a mechanic replace the thermostat and hook the heater core back up your probably going to need a new heater core ,Replace the oil filter and change the oil ,Get a new fuel filter , get a new air cleaner and spend a weekend cleaning it all up before winter sets in ...What color smoke is coming out of the tail pipe already ?

1) new heater core !
2) new fuel filter and air filter !
3) oil filter and oil change !
4) find a radiator cowl !
5) Replace those old hoses !
6) clean the engine compartment !!!

[UkMark]

good advise Grumpy, have the cowl [took it off to drain the radiator], thought the thermostat missing was bad news, the bay is certainly a mess so again it needs some love.
my issue with the heater core is, where does the bottom outlet connect to[i can see the top hose going to the rad right now from the inlet manifold is the the top part], i assumed it was on the base of the waterpump..but cant see where...

[Grumpy old man]

Top of engine to bottom of heater core then top of heater core to top of radiator . Fix it before your engine burns up ! and please move that rubber fuel line away from the header or insure it for fire damage !


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[UkMark]

perfect Grumpy, just what i needed, spares ordered already and a promise to tidy up!

[UkMark]

New fan and clutch fitted with a shroud , and thermo stat , heater core not arrived yet.. Tried it but if anything it's running hotter even quicker .
Tested the new thermostat and it works .
Not convinced the new heater core is gonna help .
Sure I am missing something here .....

[Grumpy old man]

Being your in the UK and driving on the wrong side of the road are you sure the water pump is running in the correct direction ?

[UkMark]

Just because there's more of you on the wrong side of the road don't make it the right side

[Fitz]

quote=UkMark;6884711]Just because there's more of you on the wrong side of the road don't make it the right side [/quote]

I can still see a little. Want to poke me in the other eye with that stick?

[UkMark]

Lol ) you"ll live fitz

[AirSpeed]

UKmark can you get parts over there? I mean can you walk into a parts store and buy parts for your truck or do you have to order everything? Just curious!

[adricar1]

if he gets in touch i stock most parts here in the uk.

[Savidio44]

Don't know if you ever sorted out your heater bypass issues, but here's how I did it on my '67 Camaro. Works great, runs cool, etc. From intake manifold to fitting at top of water pump. Not a great photo, if you don't understand, let me know.

[Fitz]

Originally Posted by UkMark

Lol ) you"ll live fitz

no doubt!

[UkMark]

"Airspeed" there are a handfull of stores but most are aimed at tuning not "oe" , can be hard work to get what you need ...

[BLT gmc]

New fan and clutch fitted with a shroud , and thermo stat , heater core not arrived yet.. Tried it but if anything it's running hotter even quicker .
Tested the new thermostat and it works .
Not convinced the new heater core is gonna help .
Sure I am missing something here ...

Are you saying it is overheating? What symptoms/problems are you having? With a thermostat in place the engine will reach operating temp quicker than no thermostat. This is one purpose of the thermostat. Bruce

[Andy4639]

This may help you also. This is out of the manual. You may need to flush the radiator also and back flush it really good.

[UkMark]

That's a good point BLT, the truck only has the original warning light in the dash cluster , which is glowing red ... Quicker , much as this could be in-reliable of course, but it is spitting water out of its over flow .

[Grumpy old man]

Are you sure the thermostat is installed correctly ?

[UkMark]

Yeh ... Not sure it would fit in the housing upside down grump?

[Grumpy old man]

I've seen them installed upside down before with your same symptoms ? Are you positive it hasn't already blown a head gasket ? you don't have to see oil in the water or water in the oil is it showing any white/grey smoke when running ? Again same symptoms . it's a very basic cooling system I'm begining to think you may have plugged/ clogged water passages from running straight water or some one installed the wrong set of heads ? this should be an afternoon repair job you shoudn't be still dealing with this problem after a month ! ... Somethings just not right in Denmark ...

[BLT gmc]

Coolant spitting out of the overflow could be overheating or pressure from the combustion chamber (as Grumpy suggested head gasket). Time to measure the temperature of the coolant. If it is too hot you have a overheating scenario; if it is operating temperature and it is bubbling you are having compression leaking into the coolant system. Also you need to test your radiator cap. Will it hold the pressure it is supposed to? Good luck, Bruce

[UkMark]

Bl..dy Denmark , no Vikings or raw herring here , just her majesty's finest grumpy .

Gonna flush and back flush it to death at the weekend , will double check for heads , but no smoke , no oil .

Have to say say it's not the original motor so the rad could be too small...plus not checked the cap ( how you do this I don't know ) , I think chuck it and get a 7 bar new one ?

Lastly I could be overfilling perhaps , the light is a red herring and it's not boiling ...need the temperature gun yo arrive yo know for sure .

[mechanicalman]

Originally Posted by UkMark

"Airspeed" there are a handfull of stores but most are aimed at tuning not "oe" , can be hard work to get what you need ...

E-bay?