Overheating

[keith_b]

Bought a 98 grand vitara Mazda diesel engine. It was going fine until i tried pulling a trailer and it over heated and bust the bottom hose. Changed the stat got rad flush and all seamed ok but fri coming home from work it started to boil again. It seams to boil and blow the water out the expansion bottle. Oil seams fine so don't think its the head gasket. Anyone any ideas on what to try next. Im thinking its the rad is choked but not sure any way i can check this? Any help is appreciated.

[darren C]

does the water in rad look contaminated?
is it building pressure all the time or just towing?

[pauliesx]

take the water pump off and check it. if its only when under pressure like toeing or going up hills could have a flow problem in the rad. take it out and get a flow test done. should only cost about 30 euro to check it. plus make sure the system is air free.

[keith_b]

does the water in rad look contaminated?
is it building pressure all the time or just towing?

Just under hard driving really and the water looks fine.

[keith_b]

take the water pump off and check it. if its only when under pressure like toeing or going up hills could have a flow problem in the rad. take it out and get a flow test done. should only cost about 30 euro to check it. plus make sure the system is air free.

With the rad cap off i can see the water moving getting faster with revs would that mean the water pump is ok?

[Dunnedriftin]

Id say the rad is blocked solid cause no or very little circulation of water!

[pauliesx]

does sound like rad trouble lad. evan had ths trouble in my s14a last year when i had the standard rad in it. would only happen when i drove on hard or long spins. the rad was half blocked in the end.
i would go there first . maybe check the rad cap aswell.
any white smoke out the back or missfiring????

[k1984w]

RADIATOR CAP went on me a while ago coolant spitting out the overflow and would eventually start overheating

[keith_b]

RADIATOR CAP went on me a while ago coolant spitting out the overflow and would eventually start overheating

Thats what i though first but the temp guage goes up near the top and them it starts to boil over so my guess is the rad but don't want to spend €200 on a guess. I pulled of the top and bottom hoses on the rad and put a water in top of rad and it seemed to flow out the bottom fine but im guessin its not goin through all the fins and not cooling properly. Anybody in the kilkenny area to flow test a rad? As long as the head is ok i suppose its not all bad.

[keith_b]

does sound like rad trouble lad. evan had ths trouble in my s14a last year when i had the standard rad in it. would only happen when i drove on hard or long spins. the rad was half blocked in the end.
i would go there first . maybe check the rad cap aswell.
any white smoke out the back or missfiring????

No smoke or missfiring. I dont think its the rad cap because when she overheated first the bottom rad hose bust so im guessin the rad cap held the pressure? How would you know if the rad cap was ok?