Avensis t180 Dilemma

[Jawal]

Hi all. I've got a t180. Over the last year it's been a bit smokey but nothing too much (unless it's cold). A week or two back I took it to Toyota, who took one look, said low coolant - white splatter - leaking top cap... The head gasket is gone, we can do some digging if you want but that's our diagnosis. 

I took it back and took it to my local garage who said it's fine and then the dealer I bought it from who did a sniff test which came up clear. He topped it up and said see how you go. 

Since then I've replaced the cap, it's lost more coolant and flushed the system and refilled. And it's still lost more coolant...

It's never overheated and runs great. But I know I can't keep pouring coolant in. 

What should I do next? Could a new thermostat help? Or do I bite the bullet and tackle the head gasket? 

If the head gasket repair is the only way is it better to get a reconditioned engine dropped in? If so, is it even worth it? 

Cheers

 

[Heidfirst]

have you checked underneath for signs of coolant (not  condensate from air conditioning)? It's not uncommon for the water pump to weep & some people have had leaking radiators.

[Jawal]

Never noticed it, thanks for the tip, I'll have a look.  When I drained the system though I discovered a lot of pink across the sump. It's definitely coming out of the filler cap though. Seems to only be on bigger journeys though. 

[alan333]

Coolant coming out the radiator cap would suggest a couple of things...

It could be under increased pressure from combustion gas entering the water chambers, but a sniff test should confirm this.  If it's bad you can sometimes see bubbles forming in the header tank with the engine running.  The coolant could also smell 'exhausty', might be oily, and discolour quickly.

It could be getting too hot, thus expanding and 'boiling out'.  This would be from a problem elsewhere in the cooling system.

The cooling system works in (sort of) two different areas: one is a small circuit of just the engine and heater (to allow quick heating up), and the other area includes the radiator (to cool the water once it gets too hot within the small circuit).  The circuit is pumped by the water pump, and the thermostat controls when the second circuit 'opens'.  If the thermostat is jammed open the car will take forever to get warm, and if it's jammed closed it'll overheat (but as the temp gauge is normally in the 'small' circuit, it would tell you).

A blocked radiator (or blocked radiator cooling fins) could cause overheating, as could a faulty water pump, but my money's on the head gasket.  Personally, I'd try another sniff test first.

[Jawal]

Well it does take a long time to heat up, that's for sure... Another sniff test is probably a good idea though. 

If it is the head gasket am I best off cutting my losses and getting shot of it, or trying to repair it? 

[Heidfirst]

this series of engines is known to take a long time to warm up even at the best of times. 

[Jawal]

The thing I don't understand is it never overheats, even if I thrash it. 

[TomdeGuerre]

It will overheat if you lose enough coolant, it's only a matter of time. You may also have a thermostat stuck wide open.

[Jawal]

Thanks Tom, if the thermostat was stuck wide open what would be the signs? And how could I check? 

[TomdeGuerre]

If the thermostat was stuck wide open the engine would take a very long time to heat up, might never get to its normal operating temperature unless on a hot day in stop/start traffic or heavy hill climbing. You  would also have a very poor heater in the cabin. Cure is a replacement thermostat plenty vids on the web eg https://www.youtube.com/watch?v=oTr-zYqwCdc

 

 

 

[Jawal]

Hmmm, I'm pretty sure it does get to temp (about half way up the gauge) and the heater blows hot. If the thermostat isn't gone is there any other reason that the coolant could be coming out? 

[TomdeGuerre]

1 hour ago, Jawal said:

Hmmm, I'm pretty sure it does get to temp (about half way up the gauge) and the heater blows hot. If the thermostat isn't gone is there any other reason that the coolant could be coming out? 

Could you go out and take several (10+) photos of your engine showing where you can see coolant leaks then post them up here? Thanks

[Jawal]

Not with the car at the moment but it's pretty much all consistent with coming out of the filler cap and the vent tube then spilling down the front left of the engine and running down across the sump. I  think that the car could idle all day and it wouldn't happen. I'll get some photos later. 

[Jawal]

Sorry, no pictures yet. Another question though, if the head gasket is going is there a chance that if I get it stripped down now a new gasket will solve the problem or am I almost certain to need a new head? 

[Heidfirst]

you can't tell until it is stripped.

Toyota say that these should not be skimmed but some people appear to have had success going that route.

However, if it is a head/head-gasket issue then if all you do is replace the gasket you can be sure that some point the problem will reappear as you haven't tackled the underlying cause of carbon build up.

 

[alan333]

I don't have much knowledge of the engine other than from the net, but I reckon if I had one, and only renewed the gasket...I'd drive it forever more with one eye on the temp gauge.  I'm with Scott, it'll come back and bite you in the gluteus maximus  when you least expect it.

[Jawal]

If it is carbon build-up, how best to go about cleaning it out? 

Cheers 

[TETOCONPOLERA]

First test if your fan temperature sensor is ok.

Mine was cover in mud and doesnt turn on the cooling fan when it should and the radiator cap drop coolant

[frankie406]

Did the op ever get it sorted?

[Konrad C]

On 7/19/2016 at 2:32 PM, Jawal said:

If it is carbon build-up, how best to go about cleaning it out? 

Cheers 

I think trying something like BG244 or similar to run through the fuel system. Or strip down the inlet, exhaust and EGR. 

I don't see how this will help if there is a coolant leak somewhere. I had a coolant leak which turn out to be a crack in the plastic part of the radiator. It took a while to find until it got worse and more easy to detect. Only then did the drip happened and was traceable. The OP had the sniff test that was negative, but the head gasket could be leaking to the outside, not the cylinders! 

39 minutes ago, frankie406 said:

Did the op ever get it sorted?

It can be frustrating when you don't get a conclusion to a problem. I like to share any solutions or say what the final outcome, so may help others in the future.

[frankie406]

If the op can get some UV leak detection fluid with a UV light it could be easier to find.

[Jawal]

Hi, as yet there's still no solution to the problem... Some good ideas here though, thank you. I'll have a go with the BG244 and keep on meaning to get round to doing the EGR.

The car still looses a little water from time to time. I'm having to add about 250ml every couple of hundred miles. I still haven't worked out if it's dripping when it's still (there's too much plastic underneath really).

What I did notice the other day that I thought was really odd was that the level looked low then when I took the cap off the level rose to the point that it was OK. Not sure what this means.