No Cabin heating and coolant issues

[Jpadie]

Hi 

I've got the 180bhp diesel rav4 which I think is the T180 in the UK.  

Recently the cabin heating packed up, lots of white smoke out the back and the anti-freeze level seemed to go down.  I topped up the anti-freeze several times and it got better.  

When I came back from several weeks away the coolant was again low and I added some rad-weld and topped up with anti-freeze.  By this time I've added 4L so I suspect that it's just the new stuff that's in there.  After 50 miles there's no more coolant in the expansion tank, but there is coolant splashed around the engine compartment.  

This makes me think that there might not be a leak but that something else might be going on.  Still no heating in the cabin though; and the car is running ok.  The temp gauge on the dash does it's usual slow rise until hitting fractionally above the mid-point after a couple of miles, which makes me think that the temp sensor is working, although on the other hand the splashing suggests that the coolant might be overheating and boiling out of the safety valve, which suggests perhaps that the temp sensor is not working.

Can anyone point me in the right direction for troubleshooting this, please?  the fans _seem_ to be engaging normally.  It's parky here in the south west of france! 

Separately are there any workshop manuals available for the Rav4?  i pop into Halfords every time i'm in the UK in the hopes of finding one but to no avail so far.

thanks

Justin

[vwchico1,6i]

Hi 
I've got the 180bhp diesel rav4 which I think is the T180 in the UK.  
Recently the cabin heating packed up, lots of white smoke out the back and the anti-freeze level seemed to go down.  I topped up the anti-freeze several times and it got better.  

When I came back from several weeks away the coolant was again low and I added some rad-weld and topped up with anti-freeze.  By this time I've added 4L so I suspect that it's just the new stuff that's in there.  After 50 miles there's no more coolant in the expansion tank, but there is coolant splashed around the engine compartment.  
This makes me think that there might not be a leak but that something else might be going on.  Still no heating in the cabin though; and the car is running ok.  The temp gauge on the dash does it's usual slow rise until hitting fractionally above the mid-point after a couple of miles, which makes me think that the temp sensor is working, although on the other hand the splashing suggests that the coolant might be overheating and boiling out of the safety valve, which suggests perhaps that the temp sensor is not working.
Can anyone point me in the right direction for troubleshooting this, please?  the fans _seem_ to be engaging normally.  It's parky here in the south west of france! 
Separately are there any workshop manuals available for the Rav4?  i pop into halfords every time i'm in the UK in the hopes of finding one but to no avail so far.
thanks
Justin

Hi im not from uk but iv seen this normally at the waterpump seal if it leaks the belt throws it all over the engine bay.

Maybe also check the pipes that come out the firewall maybe a pipe is leaking there causing the coolant to leak leaving you with no water cycling through the heater core in the car kind of hard to tell with out images.

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[Jpadie]

thanks.  Does the T180 have a timing belt?  i thought it had an internal chain. 

yup - possible that the water pump is leaking.  they usually weep a bit though, I had thought.  

[Heidfirst]

Hi Justin, welcome to TOC 

The T180 cam is chain-driven.

The fact that your car lost coolant whilst standing idle for weeks suggests a leak - as you mention weeping water pumps are not unknown.

However, you should also be aware of the potential head/head-gasket issue on these engines (albeit only a very small % actually develop it) - 

 

[Jpadie]

thanks for the welcome - in fact I've been a member since 2009 (I think) but I can't access my account for some reason.  

So I've been out and poked around the car a bit.  Taken the oil drip cover off, filled with coolant (Halfords stuff).  the first time the coolant dropped from the level to almost empty in five minutes.  I imagine that was an air block.  So I topped it up again with the tap open, the closed the tap and started the engine.  Left it running for 20 minutes and at the end the cabin temp was warmish.  I killed the engine then cracked the cap of the coolant very gingerly.  Lots of pressure in there, which should mitigate against a leak unless the leak is very slow.  Coolant was highly frothed (pressure release?) but all there.  Will leave it over night and see what happens.  Whilst the car was running I had a good look underneath and although I could certainly see globs of coolant, I could see no obvious leaks - the globs probably being from a a shaky pouring hand in my old age. 

Does this point towards a temp sensor issue?   

incidentally the oil level is v high.  at least 2cm too high on the dipstick. I'll resolve that tomorrow but would that cause issues?

some photos and video for your delectation. https://photos.app.goo.gl/OzzrZlSELJwCQwRU2

[vwchico1,6i]

thanks for the welcome - in fact I've been a member since 2009 (I think) but I can't access my account for some reason.  
So I've been out and poked around the car a bit.  Taken the oil drip cover off, filled with coolant (halfords stuff).  the first time the coolant dropped from the level to almost empty in five minutes.  I imagine that was an air block.  So I topped it up again with the tap open, the closed the tap and started the engine.  Left it running for 20 minutes and at the end the cabin temp was warmish.  I killed the engine then cracked the cap of the coolant very gingerly.  Lots of pressure in there, which should mitigate against a leak unless the leak is very slow.  Coolant was highly frothed (pressure release?) but all there.  Will leave it over night and see what happens.  Whilst the car was running I had a good look underneath and although I could certainly see globs of coolant, I could see no obvious leaks - the globs probably being from a a shaky pouring hand in my old age. 
Does this point towards a temp sensor issue?   
incidentally the oil level is v high.  at least 2cm too high on the dipstick. I'll resolve that tomorrow but would that cause issues?
some photos and video for your delectation. https://photos.app.goo.gl/OzzrZlSELJwCQwRU2

Thats interesting i also know that it might boil like that if the lid is not working correctly.

Then pushes it out the overflow at the top.

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[IanML]

The oil level too high might be an indication of coolant in the sump, due to a head gasket problem.  Oil is lighter than water, so the coolant would tend to pool in the bottom of the sump.  You could crack open the sump drain and see what you get out.

[Jpadie]

@vwchico1,6i - what do you mean by the lid not working?  that it doesn't form a seal?   If the cap were working correctly, and holding the volume broadly constant, I'd expect that pressure within the circuit increases with temperature (a crude restatement of Boyle's law).  Conversely, with the rapid decrease in pressure (cracking the cap gingerly) I'd expect that there would be a very rapid increase in volume (gasifying) which I'd imagine would lead to the froth, until the temperature decreased enough.  I will try again during the light today and see whether anything more can be observed in the chambers.

 

@IanML - I need to crack the sump and drain some of the fluid anyway, so will verify this.  However I suspect it is more likely that it was one of my children misunderstanding the dipstick.  I think on the RAV4 the levels are shown by the little protrusions on the stick, whereas on other cars the oil needs to be between the bottom and top of the twist.  on the rav4 there is a twist directly above the section with the protrusions.  Confusing.  

 

any thoughts on the squishy stuff shown in the video?  and any thoughts on locating and testing the right temperature sensor?  

[alan333]

It sounds like a head gasket problem to me - the water is entering the combustion chamber and the white smoke was the engine burning it off.

Fill the cooling system properly.  Set the cabin heater to max heat (not the fan speed, just the temp).  Fill the radiator first if it needs it, then fill the expansion tank to normal level.  Leave the expansion tank cap off and run the engine until hot.  Top up the expansion tank if necessary while the engine heats up (the level could decrease as it gets rid of air pockets).  DO NOT let the expansion tank get empty.  Beware the expansion tank level might suddenly drop when the thermostat opens.  Observe the water in the expansion tank.  If it's bubbling then it's combustion gas entering the water chambers and boiling it.

[Jpadie]

@alan333  thanks for the comment.  I'm doubtful it is the head gasket for the following reasons:

• no increase in oil consumption;
• oil is still the normal dark colour.  no grey/milky discolouration
• although there is the billowing smoke out the back from time to time (like the fifth injector burn off), i've noticed no loss of compression (for a coolant/cylinder leak) but will borrow a tester and do a proper leak down test.
• i've not seen any coolant leaking below the manifold. 
• engine is not overheating. 

Also - I did not know that there was a way to refill the radiator separately to the coolant expansion tank.  any clues as to where the fill port is? 

[alan333]

Bear in mind there's three things which can mix if a head gasket fails: water, oil, combustion gas.  Perhaps you have water and combustion gas mixing, not necessarily water and oil (although you mention that you oil level was high).

Sorry but I didn't notice one of your pics was a video - isn't the pipe with the cap with the big H on it something to do with the air con?  I'm no air con expert but I'm pretty sure there's normally a high (H) pressure valve and a low (L) pressure valve.

Also I'm not familiar with your particular engine, but normally there's a cap on top of the radiator, perhaps hidden below some plastic trims?

Edit.. my earlier post states "Fill the radiator first if it needs it".  I should have said "fill the radiator first if it needs it, and refit the radiator cap".

[Jpadie]

thanks again for the reply @alan333. 

 

if there was an oil/coolant leak then i'd see rubbish in the engine oil or oil in the coolant.  nothing visible so far either way but i have yet to crack the drain screw.

if there were a leak to air then i should see oil or coolant splattered around the engine block.  i'm not seeing anything _obvious_ yet, but i will clean down the block a bit and test again.

or there could be leaks to the cylinder.  if there were a coolant leak to the cylinder then that might well explain the coolant escaping through the pressure valve (as it would be being pressurised by the engine compression); but there should also be loss of power and overheating.  which there isn't.  this is still a possibility though - perhaps a small leak.   i will pressure test the block on saturday.  

sfaik the rav4 uses an expansion tank system rather than an overflow.  i am not aware of any radiator fill port other than the expansion tank.  

the other reasons that the fluid could be overheating and escaping the pressure relief valve are:

1. faulty 'stat (any clues for diagnosing this?)

2. faulty cap (don't think so as even after several days there is a pressure release hiss when i take the cap off)

3. rad fans not working.  i will test this but on previous occasions this has been ok.

I will do the test that you suggested, thank you.  

 

[Jpadie]

@alan333

so ... no coolant in the oil tank.  but it was _way_ overfilled.  I took 3L out before the level was down to the right point.  I'm surprised that the car didn't complain earlier as I guess the crank may well have been causing the oil to have become aerated.  But the oil pressure has consistently been ok, and there has been no noticeably overheating. 

Since last night there had been no loss of coolant fluid.  Which leads me back to an escape valve issue.  

I ran the test you suggested and there was a small drop in fluid in the expansion tank, which I topped up.  I left the engine running for half an hour (with heat on max as you say).  cabin heating was ok, the rad fans were both working.  But the coolant was boiling and as a result it was foaming and overflowed (slightly) the top of the funnel I was using.  There was no obvious bubbling as the coolant was heating up, which suggests against a head gasket leak does it not?  Of course without the cap on, the coolant boiling point is going to be a lot lower than normal (about 30 degrees C); so the presence of boiling in an unpressurised system is not in itself evidence of pressure leakage from the head gasket.  

next step is the leak down test.  Kit is on its way and, God willing, may be here tomorrow.  Very much hoping against a head gasket failure as I really don't fancy a couple of days out in this weather taking the engine to bits.  It will be my first too...

[alan333]

3 hours ago, Jpadie said:

1. faulty 'stat (any clues for diagnosing this?

The stat should be closed when the coolant is cold, therefore the water is only pumped around the engine and heater.  As it heats up, the stat opens thus allowing hot water to flow to the radiator by way of the top hose.  The radiator cools this water as it flows through (assisted by the ram effect of driving, and/or the cooling fans as needed), and replacement cool water is drawn back into the system from the bottom hose.  Therefore, feel the temp of the hoses as the engine heats up - you should have a hot top one and a cool/warmish bottom one.

Alternatively, for a more thorough test - remove the stat and put it in a pan of water and heat it.  You should physically see it operate at about 90-95 degrees IIRC.

[Jpadie]

Thanks.  I hadn't considered that the stat might not be a valve linked to the ECU and a sensor.  How silly of me.  I will go hunting for its location and pull it for testing. 

[Heidfirst]

Another reason for a high oil level can be diesel contamination from interrupted DPF regeneration (DPF regeneration also causes white smoke/vapour). Don't think that there are a lot of reports of this on the 2AD but e.g. Mazda's 2.2 diesel is notorious for it.

[Jpadie]

Thanks @Heidfirst.  Good to know.  In this case it was due simply to overfilling.   I've done 1200 km with 3L too much oil in the engine, but the cabin pressure/coolant issue predates this. 

i tried to pull the 'stat this evening but lost the light and all feeling in my hands; so decided that discretion was the better part of valour and will wait until the morning.  

No news from Mr Bezos on the despatch of the leak test kit, so that may have to be next week now.  In the meantime I'll keep an eye on the coolant level. 

thanks.

[Jpadie]

Hello again all ... 

i just took the car out for a 20min spin, after having left it idling for a 40 mins.

when I started the drive, the coolant was spurting out of the expansion valve.  likewise when I left it.  The coolant was very foamy too.  So this is where the coolant is getting out of the system.  

the inlet and outlet hoses to the radiator were warm, but not hot.  even after so long.  The temp gauge on the dash was the lowest I'd ever seen it (in a steady state) - it was about a quarter up from the bottom.  The cabin thermostat had been at 'hi', and whilst the cabin was warm it was not the fug that I'd have expected after so long.

Does this provide any further useful data for a diagnosis?  seems to me to be  one or more of the following

• the cylinder block,
• the expansion tank cap
• thermostat stuck
• possibly the heater core/control valve

I've ordered a new thermostat which should arrive on Tuesday.  I realised that I didn't want to pull the stat without replacement gaskets.  hopefully the weather and topping up the coolant will keep things manageable for a little while.  

[Jpadie]

Just to update this thread, the car passed its MOT today.  Emissions well within norms.  So that's a relief 

The leak down test has yet to be performed as I got sent a kit for testing fuel pressure in error.  New kit has arrived so a job for tomorrow.  

What is interesting is that the inlet and outlet pipes from the expansion reservoir are warm but not hot.  40C or so.  And the refrigerant spurting out of the reservoir is highly foamed but not at all warm.  Maybe 25C.  

Does that make an air leak more likely and a head gasket leak less so?  The engine was warm after the MOT (when I tested the coolant). About 1/4 of the way up the dial.  

Thanks

Justin

 

 

[Jpadie]

Afternoon all, 
I spent a couple of hours compression testing the cylinders (hope I followed the right protocol - see below) and it looks to me that all four are compressing adequately ( all of them to 320 psi on the nose).

I hope I'm right in thinking that this rules out a head gasket failure?

The protocol  i used is:

1. remove Battery ground
2. remove the insulation, the nuts and then the ground strip from each of the glow plugs
3. use degreaser then compressed air to clear the surrounds of all the glow plugs
4. remove the right most glow plug and insert a fake plug.  
5. reconnect Battery ground
6. disconnect the ignition line from each of the cylinders
7. connect the manometer 
8. turn the engine over until the manometer stopped going up (felt like 4 turnovers)
9. remove fake glow plug, reinsert real one, move to left and repeat.  

 

Assuming this does rule out the head gasket, are there any clues as to what to investigate next?  The foaming starts very rapidly and consists of lots of tiny bubbles.  the fluid is under pressure (and escaping out of the overflow valve) but the liquid is not hot; the inlet line from the top of the rad is warm but not uncomfortably so.  It does not appear that there is liquid leaking from anywhere else, but it's very difficult to be sure as then the stuff starts coming out of the overflow it drips everywhere.  

even if i had the cash, there's no chance of getting this fixed at any local garage this side of mid january, and I'm in the boonies.  so any help you can give may just save Christmas for the household! 

thanks in advance

justin

 

[Jpadie]

Hi

I appreciate that I've probably exhausted everyone's patience and goodwill on this thread.  And am unlikely to get further substantive responses.   I am grateful for the engagement.  

May I asked one more brief favour and request some pointers to diagnostic forums that members have found helpful in the past?  

 

Thanks

Justin

 

 

 

[alan333]

Have you had a sniff test done?  I've not had any dealings with one myself so I can't comment on how reliable/accurate they are... but even tho your compression test seems to give good results - everything else points to head gasket failure (IMHO).

[Jpadie]

@alan333  not a formal gasometry test, no.  but there is no smell of combustion gas coming from the reservoir.  just the usual smell of glycol.  not even that pungent as on the recent journeys I have done the ECU reports that the coolant temperature has never exceeded 65C.  

I guess it is possible that the gasket only leaks when there is some heat in the engine (so perhaps by the time that I did the compression test, the leak had resealed), but I do find it difficult to believe in an HG failure when the pressure test is good and identical across all four cylinders - is it usual that a leak down test is good but the head gasket still blown?  

Perhaps I did the test incorrectly.  I can try to run the test again when the engine is hot and see what happens.  I should have a couple of hours on Saturday.

The toyota manual seems to require taking the whole engine out of the car in order to change the head gasket.  This seems quite extreme.  Can the cylinder head not be removed in situ?  I can see why you might need to remove the engine if the block needs skimming.

I'm wondering whether it is possible that the coolant i got from Halfords might have been contaminated with or mislabelled screen wash, except the foam does not feel soapy.  

Unfortunately the UV diagnostic is not helpful as the stuff spurts everywhere from the pressure release nozzle.  i wonder whether it might be helpful if I sluiced the engine down with clean water and then attached some aquarium hose to the nozzle to capture the stuff that comes out.  the use a uv lamp to see whether there are leaks elsewhere (I'm thinking more air getting into the circuit than water getting out).  

@IanML  thank you very much for the pointer.  

 

[vwchico1,6i]

So im guessing you happy with the lid like i said.

I only use toyota coolant.

When i bought my Rav the coolant was almost empty

I drained all old coolant out and put in Toyota's brand of coolant in and 4000 km i have not had any drop in the coolant.

Mine has same as yours coming out the over flow.

Does yours have a radiator cap?that could also be an issue.




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[Jpadie]

no radiator cap on my rav4.  there is a pressure cap on the reservoir that could be faulty.  I don't know how to diagnose that without simply buying another (one is on order) and I can't quite see the physics of how a fault in that cap could cause foaming.  The cap holds pressure just fine (significant sound of pressure release when removed).