Engine Overheated

[scott.mohekey]

Last night we ran it with the cap off for a while, and now and then bubbles were coming up out of the radiator, there also seemed to be a small film of oil in there.. so its looking like a head gasket. Tonight we're going to do a compression test to rule that out, and if thats not it, we'll take the radiator out and get it tested.

[Davezj]

just remember when doing a compression test to disconnect the crank and cam sensor under the y pipe to stop fuel and spark.

you can get a siffer test done that will detect exhaust gas in the coolant water. it look like a hydrometer, but the liquid in the tester goes blue or green i think if the gases are detected.

EDIT:- just thought it not a VR-4 is it. if you do get lower than expected compression then poor some light oil into the spark plug hole and see if the compression increases. as a definate proof. the light oil will fill the hole/crack just enough to push the compression reading up.

[scott.mohekey]

This is a NA 6a13, will the crank and cam sensors be in the same place?

[Davezj]

not sure but they should be round the somewhere on the cam gear end of the engine. i wil check the manual. the 6A13 engine manual should be in the library somewhere.

the compression test procedure is on page 11-B8

[scott.mohekey]

Thanks, I'll have a look.

[Davezj]

attached it anyway mate.

[scott.mohekey]

I've found a connector at the top left of the engine for the crank angle sensor, but can't seem to find a cam sensor anywhere.

[Davezj]

i think the 6A13 engine only has the crank sensor to be diconnected. have a look at section 11.pdf i attached above page 11-B8.

[scott.mohekey]

That's where I was looking. I can't see a cam sensor anywhere in the manual.

[Davezj]

I think you are right the none turbo engine doesn't have cam sensor that can be disconnected. but you will get the same result "no fuel, no spark" if you just do the crank sensor.

[Subaru ETA]

a compression test is abit of a waste of time IMO. id do a teekay test on it first. as i have said before though - something else has prob let go to make it over heat, then blow the head gasket. such as blocked rad or bung thermostat

[martin_y]

Yeah, I was going to say that a blown head gasket is likely a SYMPTOM of something wrong, rather than the CAUSE.

My Money is still on blocked radiator. Even if you can flow water through it with the pipes off, it doesnt mean its cooling efficiently, and it doesnt mean water is free to flow all over the radiator either. Remove that Rad, and take it to be checked at a radiator shop.

[scott.mohekey]

I swapped the radiator with a spare tonight, and it seems to have fixed the overheating problem.

I've noticed that water is leaking out from around the water pump. So I'm going to have to get that looked at, and I might as well get a teekay test done at the same time to see how the gaskets are.

[Ryan]

Good stuff, glad you're making some headway with this

[scott.mohekey]

I drove around a bit last night, and to work this morning. I'm having to top up coolant before each trip, the overflow bottle is empty each time, but the radiator is full to the brim?

Also, I can feel a sort of knocking through the accelerator cable now and then. I think a mate has the gear needed to do a teekay test, so I'll try and arrange that for tonight, and if I need gaskets and they're not too expensive, I'll check the water pump and do the gaskets this weekend. Otherwise I'll wait till I get paid to get someone else to do the pump.

[scott.mohekey]

Where in NZ an I get a new water pump from?

[Fully]

Goto the corner of Durham and Byron st (bottom of the bridge) I dont know the name for sure, but its parts world or something like that.
There is always BNT on Montreal St.
Donnithrone Sims are expensive.

Shop around, let your fingers do the walking

[scott.mohekey]

Thanks, I got a new pump from parts master for $96.

We took the intake and cam covers off last night, and found that the center front spark plug hole was missing an oil seal. Even more disturbing, there was a small piece of broken plastic lodged under one of the valve springs. Also, the center front inlet had some oil in it.

Im going to take some photos of the various parts and put them up shortly, then we'll start at taking the heads off.

[Davezj]

why would you take the heads off if you didn't need to.

i am assuming the none turbo engine has the water pump in the same place as VR4.
if you are doing the water pump i hope you are doing the cam belt, pullets, etc, as well. while you are doing the water pump check the crank oil seal if it is leaking do that as well.

it is not uncomon to get oil in the spark plug hole as the seal on the rocker cover is a bad design. just a new set and fit them as the intense heat of the engine bay can cause these saels to go hard and they will not seal properly after that. Once you disturb them it is difficult to get them in exactly the same place to make the seal tight.

[scott.mohekey]

I'm taking the heads off to replace the gaskets. I'm having to take damn near all of the engine apart to get to the water pump, so I figured I might as well do them while I was at it.

As for the spark plug oil seal, I bought a set of replacements which also comes with a rubber seal for the entire cam cover, something that was entirely missing from the engine previously!

Can anybody think of why these would have been removed? Does it help the spark plug oil seals seal better?

Also, there seems to be a lot of oil on the underside of the engine. The whole block is wet to the touch, in some places oily, other places greasy/grimey. I figure I should clean it all off so I can figure out where the oil is coming from. In retrospect I should have done that before stripping it down.