Coolant Issue

[DGH-ST202]

Hi All,

I had a coolant issue for quite some time in my Celica that I've known about but not bothered doing much about.

Firstly a small point, I know I need a new rocker cover gasket as oil is getting in one of the spark plugs when they were changed few months back, any tips on that or which one to buy?

 

So with the coolant, it was overheating a lot when idle or in slow-moving traffic; I took to the mechanic, and he saw there was no coolant in my radiator it took a lot to fill it up and it did fix it from there, I replaced the radiator fan at the same time as it was getting noisy when idling, I thought it was the fan not cooling properly. So it no longer overheats, but it still has a couple of issues. Every little while, I have to top up the radiator with coolant; the reservoir does not go down at all and stays the same. Plus, if the car has been used well, with high revs, etc. when I open the bonnet, there's coolant spill over the engine bay, not always excessive, but when I had it on track at Silverstone, it was excessive (I don't track the car anymore). So I am wondering is it the thermostat or is something else? the radiator looks fairly new and was replaced about 2 years ago, does have little dents in it from chips I expect but is all okay. I do want to get rid of this issue as its the only fault with the car at the moment. I was also wondering could the radiator cap be at fault? Maybe the car as radiator is full and coolant boils it squirts out the top or is there a leak elsewhere?

 

Thirdly, a little side note: I had an oil leak on the rear of the engine but not excessive on my motor that was just done, Do you have any advice on what it might be?

 

Thank you all

[Old Red Celica]

Just because the rad was replaced 2 years ago, does not rule it out.

 Has it been pressure tested? Has the block been flushed?  So many questions!!

[DGH-ST202]

6 minutes ago, Old Red Celica said:

Just because the rad was replaced 2 years ago, does not rule it out.

 Has it been pressure tested? Has the block been flushed?  So many questions!!

I've not pressure tested it or the block( not sure what block).

[Xanadu]

3 hours ago, DGH-ST202 said:

...I need a new rocker cover gasket ...any tips on that or which one to buy?

 

I think most people choose to fit a genuine Toyota gasket.

 

It comes in two parts: 11213-88460 and 11214-88460

[Old Red Celica]

The block as in Engine block, you could have "Radweld" blocking cooling channels. 

[DGH-ST202]

9 minutes ago, Old Red Celica said:

The block as in Engine block, you could have "Radweld" blocking cooling channels. 

What would you recommend i start with? Sounds quite drastically bad. I was hoping thermostat change, change radiator cap with flush and be alright

[_Chris_]

There's something fishy about the overflow tank not changing level while it's blowing coolant out of the rad.

Check you have a hose from the side of where the radiator cap goes on to the cap of the overflow bottle. Then check there is a hose on the inside of the cap for the overflow bottle long enough to go down to the bottom of the bottle.

The system works by allowing coolant that goes out past the pressure of the radiator cap to flow into the expansion bottle. When the engine cools down and the coolant contracts the coolant is sucked back into the radiator.

The radiator cap should have a rubber seal to seal the cap against the upper flange of the radiator. This ensures the coolant flows correctly to and from the expansion tank. If it doesn't seal, collant can blow out under pressure and worse, when the coolant contacts it will suck in air rather than the overflowed coolant.

Also check that there is no blockage in the pipe from the radiator, through the overflow cap and down to the bottom (blow in the hose and check you get bubbles in the coolant in the overflow tank).

 

Beyond that, with repeated overheating there is a possibility of a leaking headgasket. This will tend to blow coolant out when driven hard as the combustion gasses leak into the coolant system and pressurise it. Check the above first though, with headgasket it would normally blow coolant and gas out through the overflow tank, the level would not remain unchanged.

 

[DGH-ST202]

2 minutes ago, _Chris_ said:

There's something fishy about the overflow tank not changing level while it's blowing coolant out of the rad.

Check you have a hose from the side of where the radiator cap goes on to the cap of the overflow bottle. Then check there is a hose on the inside of the cap for the overflow bottle long enough to go down to the bottom of the bottle.

The system works by allowing coolant that goes out past the pressure of the radiator cap to flow into the expansion bottle. When the engine cools down and the coolant contracts the coolant is sucked back into the radiator.

The radiator cap should have a rubber seal to seal the cap against the upper flange of the radiator. This ensures the coolant flows correctly to and from the expansion tank. If it doesn't seal, collant can blow out under pressure and worse, when the coolant contacts it will suck in air rather than the overflowed coolant.

Also check that there is no blockage in the pipe from the radiator, through the overflow cap and down to the bottom (blow in the hose and check you get bubbles in the coolant in the overflow tank).

 

Beyond that, with repeated overheating there is a possibility of a leaking headgasket. This will tend to blow coolant out when driven hard as the combustion gasses leak into the coolant system and pressurise it. Check the above first though, with headgasket it would normally blow coolant and gas out through the overflow tank, the level would not remain unchanged.

 

Fair play that's a big answer,I will have a look at that and come back. Thank you bud.

[Old Red Celica]

I wondered if there was any pipework or galleries blocked with Radwell.

As Chris has mentioned that the header tank should rise and fall as the engine temperature fluctuates.

[DGH-ST202]

1 hour ago, Xanadu said:

 

I think most people choose to fit a genuine Toyota gasket.

 

It comes in two parts: 11213-88460 and 11214-88460

I was looking at this https://gt4-play.co.uk/shop/cam-cover-gasket-genuine-toyota I'm guessing it's the same?

[Xanadu]

I would be much clearer if they stated the part numbers in the description.

 

You could also try TCB

 

[DGH-ST202]

6 hours ago, Xanadu said:

I would be much clearer if they stated the part numbers in the description.

 

You could also try TCB

 

I thought rocker cover gasket was just one piece that went around the rocker cover?

[_Chris_]

The gasket is 2 piece as it also seals round the spark plug holes. Both GT4-play and TCB are excellent suppliers.

 

You will need to put a little bit of silicone sealant in the corners where it goes up over the bearing caps.

 

I would get to the bottom of the coolant issue first as it may need to come apart again if it does turn out to be head gasket.

[DGH-ST202]

On 30/10/2024 at 20:36, Old Red Celica said:

I wondered if there was any pipework or galleries blocked with Radweld.

As Chris has mentioned that the header tank should rise and fall as the engine temperature fluctuates.

 

Just googled what Radweld is and came with this: https://www.eurocarparts.com/p/holts-radweld-250ml-549772101

 

Is this something I should pour down the radiator or into coolant tank itself?

Haven't had time to check it all properly but briefly did a clean today of engine bay and did 2 x 1 hour drives today, gave it a bit of beans nothing over the top, seems a little bit of coolant dries up on the heat shield in front of the engine and little bit around, again not a lot but is a bit.

 

I will take some photos when I get a chance and look next.

[_Chris_]

DONT USE RADWELD. It is designed to fill and seal leaks, that tends to include the smaller pipes in the sytem which then stops the system working.

 

There shouldn't be any coolant esxaping except through the expansion bottle at the side. It it's on the heatshield it's probably coming from the radiator itself, which either means the cap isn;t sealing on top or the pipe is missing from the radiator to the expansion tank.

 

As per picture below, except radiator cap is usually in the middle of the radiator and not one side.

 

 

 

 

 

[DGH-ST202]

5 minutes ago, _Chris_ said:

DONT USE RADWELD. It is designed to fill and seal leaks, that tends to include the smaller pipes in the sytem which then stops the system working.

 

There shouldn't be any coolant esxaping except through the expansion bottle at the side. It it's on the heatshield it's probably coming from the radiator itself, which either means the cap isn;t sealing on top or the pipe is missing from the radiator to the expansion tank.

 

As per picture below, except radiator cap is usually in the middle of the radiator and not one side.

 

 

 

 

 

Thank you I will have a look tommorow in the light 

[Old Red Celica]

Radweld has got many people out of trouble over the years, but it's not a permanent fix. It's a bit like the liquid puncture repair gel, gets you out of trouble,  but repair shops hate it.

 

 Radweld years ago was what you put in a coolant system on the way to an auction when the rad was knackered. Just like sawdust in engine/gearbox/axle oil.

[DGH-ST202]

Still looking into coolant issue, ordered a new radiator cap for the moment to see what that does. 

 

Whilst looking under the bonnet though something I had not seen before, I found two loose connections, one black and one grey, on the drivers side coming from the alternator it looks like, I found another of these grey connection under the battery whilst I was looking around for coolant leaks, could not see the black wire though.

I am wondering if this to do with a headlight conversion as on my main beams I have some big led lights like these https://www.eurocarparts.com/p/osram-cool-blue-intense-hb4-headlight-bulbs-with-a-xenon-look-2-bulbs-48177030c

not exactly them ones but like that.

 

Just wondering if anybody knows if they're okay left like that, I mean they cant be essential surely as car is fine apart from coolant issue and passed mot recently.

@Old Red Celica @_Chris_