5-me overheating. real confused

[vinno]

hey guys..

the 5-me thats in my mx-62 keeps overheating even though i've tried everything to fix it.. Thermostat is fine, water pump is fine, i flushed the block and the radiator and they both seem to be flowing fine.. i discovered that the tensioning bolt for the water pump had snapped so in turn there was no tension on the belt so i replaced that and this is where it gets a little strange..

when i run the car it builds up heaps of preassure in the pipe entering the radiator and holds that preassure even when the engine is shut down. the engine will run fine at night and not overheat but during the day it boils. does this mean my radiator is half blocked or something? i cant think of what else it could be.

cheers guys
vinno.

[thechuckster]

remove cap when cold - if you get lots of bubbles then BHG

if no bubbles, remove radiator and flush/clean

if little fluid moving when warmed up, plumbing is wrong somewhere.

talk to Wilbo666 as he might have a smick-looking radiator out of a MX62 available for sale soon (he's about to wreck one).

[mrshin]

Sounds like something is blocked up, or the water pump has lost its ability to pump anything. Be absolutely SURE that things are flowing how they are meant to.

[vinno]

No bubbles..

water pump seems fine cause i took off the top pipe to the radiator and started the car and got plenty of water flow out that top pipe.. (this was done while thermostat was out so that the engine didnt have to be hot to do it)

[ian]

maybe an air lock
see if you can bleed out any air
if there is air in the system it just cavitatates around the water pump
ian

[wilbo666]

If it doesn't look to have a BHG, then I would be looking at the rad as the next cause...the fact that it doesn't do it at night when it is a little cooler points me to think that the cooling system is borderline, a blocked rad would have that effect...

As thechuckster says I've got a rad here that was recored only 3? years ago that will be for sale soon (not to mention a whole butt load of other mx62 parts if you need / want anything?! Manual conversion, lowering springs, ).

Swing us a PM if you want

Cheers
Wilbo

[1337_86]

How much coolant did it take when you filled it. Did it seem like a small amount. If so, I would bleed the system, and see if it takes more after that. If it's still no good probably go for the recore.

[unleashed__]

you've got an airlock.. bleed the cooling system.. make sure radiator the highest point.. if it already is then just undo the radiator cap and let it run for 10 or so minutes.. if ur radiator isn't the highest point put a funnel in the radiator and fill it up with water and watch all the air escape..

[vinno]

i dont think it is an air lock.. if u try and start the car with the radiator cap off then the water starts to rise and spill out of the radiator. that's y i'm suspisious of a blockage in the radiator.. getting another from the wreckers tomorrow so we'll c how that goes..

[BLACK77]

sounds like the prob we had with my sisters 184...$100 at NatRad for a bottom end cleanout. the guy said he "nearly kicked it over the fence" 75% blocked ...havn't had a drama since

[thechuckster]

what he ^^ said

wrecker one might be just as choked up as yours - take it to a radiator shop and get them to clean it - will probably cost about the same as an unknown 2nd-hand job.

[lexsmaz]

Sounds like a BHG ... There are a few ways to check, Smell the inside of the radiator cap & inside the radiator, if it smells fumey, ( bit like an exhaust smell ) its blown .. 2nd option, Put the thermostat back in Fill the radiator up, take off the coil lead & crank over the motor if the water rises & spills out its blown ...3rd option, Put the radiator cap on & coil lead, start up the car, give it a few sharp hard revs, then turn off, only let it run for 10 seconds or so total, then slowly release the radiator cap if theres heaps of pressure in the system, the gaskets done ... Probably best to do all three tests & best to do on a cold engine ....
Plus as you said if your boiling it during the day, alloy heads dont like to get boiled ...

[wilbo666]

I heard that he changed the rad (with one from a wrecker) and it is all good now

Cheers
Wilbo

[vinno]

wilbo..

i did replace it and it is staying cool now but it still gets a rediculous ammount of pressure in the system..

drove to work the other day.. didnt over heat at all, the car sat still for 8 hours then i opened the radiator cap to check the water and there was still a fair bit of pressure in there?? i dont understand this.

[lexsmaz]

Do the check's as i said above, you definately have a blown BHG ... Especially if its holding pressure over that period of time .... You will also be using water .....