My 1989 Royal Lounge 2.0 EFI has been overheating for the last month since having a burst hose replaced and the radiator cap renewed. I thought I had cured the fault by replacing the radiator cap which had been wrongly fitted by a Toyota dealer in Glasgow with the correct cap because all seemed fine going to work and back, a distance of about 7 miles one way. The water level in the expansion tank remained ok and I had no boiling over and the gauge neddle stayed just below the half way point which is normal in my Townie. However I recently had to do a trip of 23 motorway miles and after about 12 miles the gauge neddle started to climb so I pulled over on to the hard sholder and lifted the passenger seat and had a look to see what the problem was. The expansion tank sounded like my Misses boiling eggs on full and water was pouring out of the overflow. I allowed the Townie to cool down a little before I removed the radiator cap and discovered that most of the water had been lost from the cooling system. A friendly Police patrolman let me have use of his water and I was able to leave the motorway at the next exit and limp home keeping my eye on the temp gauge and stopping to refill the radiator once the neddle started to rise. I have since been using my Townie to get to work and all has been fine but I am going away on a 1000 mile trip in it in August so it needs to be spot on. Any ideas as to what the problem might be? P.S. All was fine prior to the hose bursting. Townie ran great and never overheated.

- (#9635) Bill, 15 Jul 03 17:16

Hi Bill.
If I remember correctly, this is the Townace that had a TRD 19psi radiator cap fitted by a garage? so there are a number of possibilities here.

The additional pressure that caused the burst pipe, may have also weakened other items as well. This may be causing the coolant to boil from insufficient pressure.

You need to carefully check the system for leaks. They may be very small leaks that won’t necessarily result in a puddle of coolant under the car, but will result in reduced pressure. One possibility is that the seals on the water pump may have started to leak, and this is difficult to identify as the pump is behind the cam belt covers.

If there are definitely no leaks, then the viscous coupling may have started to fail at high speeds. This has been known and documented on Ace Archives, and is particularly associated with motorway driving.
Basically if the temperature starts to increase at 70mph, slow down a bit and see if it returns to normal. If it does then the viscous coupling is showing the first signs of failing. Can you here the roar of the engine fan when its running hot?

Don’t be fooled by coolant boiling in the expansion tank. This is outside the pressurised system and coolant above 100°C that exit’s via the radiator cap, will boil instantly and turn to steam.
There is a possibility that your motorway overheat has wrecked the new radiator cap, which may not now be operating at the correct pressure. So its important to replace the cap once you have found the leak, or diagnosed the viscous coupling.

Regards
dave Bright Bournemouth

- (#9636) dave Bright, 16 Jul 03 2:23

Hi
i have the same problem (i think) on my space cruiser
and when im parked up or in traffic and i rev the car
i can hear the water bubbleing

couldthis be the same problem????

- (#9637) chris, 16 Jul 03 7:12

Hi Chris
I'm not too familiar with Space cruisers, but assuming that the cooling system, and expansion tank are similar or the same then, yes its entirely possible you have the same condition.

As I said in an earlier posting, its important to remember that the expansion tank is outside of the pressurised system. Water under 13 psi can be as hot as 117°C and still remain liquid. If the radiator cap lets some of this hot coolant out, it will suddenly be well above the normal boiling point of 100°C and will boil instantly turning to steam.

This may be an entirely natural event, but if you are worried, change the radiator cap, and see if things improve. Be sure to get a cap rated at 0.9 Bar or 13psi, and check for leaks, or discoloured coolant.

Hope that helps
dave Bright. Bournemouth.

- (#9638) dave Bright, 16 Jul 03 9:13

Dave - what would discoloured coolant signify?
Mine was green but is going blackish
Chris
- (#9639) chris turner, 16 Jul 03 10:31

“blackish” sadly means a serious problem.
This is only likely to be seen on Diesel engines, and is a sign that exhaust gasses are entering the cooling system. This is due to the high levels of soot in the exhaust gases. A good check is to dip a finger into the coolant when its cold, and rub it on your hand. If it stains your hand and is difficult to wash off then it is soot.
Soot in the cooling system can only mean one thing. there is a minute crack in the Head, Block, or gasket. In the early stages this may be the only sign of a crack. There may not be the usual signs such as, oil/coolant crossover, or rough running engine. However it will cause the coolant to exit the expansion tank, and the MPG may drop significantly.
- (#9640) dave Bright, 16 Jul 03 13:57

Dave, I think you might have solved my problem even though my Townie is petrol and not a diesel. My coolant is black which might mean there is a crack in the head, block or gasket. Can this be checked by a Garage without dismateling the engine?

- (#9641) Bill, 16 Jul 03 16:51

In diesel the Black stuff is soot, this is the black smoke that exits the exhaust pipe. I hadn't considered that petrol engines could turn the coolant black as well, as they burn fuel more efficiently. I guess it may be possible though if the engine is running very rich, but there might be other reasons.

With petrol engines there are ways to prove or disprove this without the need to dismantle the engine. There is a sort of sniffer that can detect petrol exhaust gasses in coolant, and a compression test can be carried out on each cylinder. The compression test may be inconclusive though because in the early stages, the crack is only a hairline crack that will act like a valve. Only very high pressure will open it up and allow crossover of gasses into the coolant. This pressure is usually only reached as the fuel starts to burn. As the piston compresses the gas, the pressure increases up to a limit. Once the fuel starts to burn, the pressure increases further, and allows the gasses through the crack. In time the crack will enlarge, and start to allow coolant to crossover. Then you will see more obvious signs that the head or gasket has failed.

This seems to be the season for failing heads and gaskets, and I my self have the same problem. Bugger.

dave Bright

- (#9642) dave Bright, 17 Jul 03 1:55

Bill, you could also ask your garage to perform a 'leakdown test'
'Bugger' is about right (lets shed a tear together)
I'm going to try the 'Car Go' liquid glass treatment next week before shelling out 30 times the price to have a new gasket fitted.
Chris

- (#9744) chris turner, 17 Jul 03 9:39

Just to say my 2.0TD had all the symptoms of a knackered head/gasket overheating and losing water out the overflow, and I was advised to have a full rebuild. I decided to try 'CarGo Seal Up' after reading about it on this site and I can tell you 3 months and 2,000 miles later, it has worked perfectly. I can't recommend this stuff enough. Make sure you definitely flush all antifreeze out before adding though as it will otherwise block up all the waterways.

- (#9745) Daryl Steward, 18 Jul 03 6:55

Had my Townie's cooling system checked out today by my local independant Toyota Garage. The problem was the viscous fan and not a leak or cracked head or block. (Thank God for that because the family holiday would have had to be canceled if it had been a crack.) The Garage said it was hard to spot the problem with the fan because it was turning but not as efficiantly as it should have been. Their mechanic took my Townie out for a run with the passenger seat up and noticed that when the temp gauge neddle started to rise the fan was running no faster than at fast idle speed. (1500rpm). I am now having it removed and replaced by an electric fan. I am also having the radiator cap replaced yet again because overheating might have rendered it useless. Thanks guys for all your help with my problem and I hope it might have helped some of you with similar overheating faults.

- (#9746) Bill, 18 Jul 03 17:02

Well, fearing head gasket (the air in system was left there by me so thats sorted now), viscous fan (not roaring like it used to despite high running temp), doing the drive it around with the engine cover up bit, earplugs, suffering heat - finally noted that nearside of rad cold and offside hot - so some blockage in rad which means hot air temp is not getting to the viscous - which is good as they are £180 uk pounds.
Hose pipe will be busy tomorrow flushing it.

- (#9822) chris turner, 21 Jul 03 9:28

but it's a crossflow rad, is it not, Chris? In which case one side will be cooler than the other. And on the townie anyway, the offside is the cool side...

If it is blocked, the hose might not do too much- but a recore is only about £100, and you know it's 100% then!

- (#9823) david miller, 21 Jul 03 10:57

I don't know David - the weather is warmer now but I'm reading 100+ degrees on motorway - It briefly read 107c recently (air lock after thermostat change - now sorted)with no viscous fan roar and at 102c now the viscous fan does'nt roar - used to cut in around 95-7 ish but its a very rare sound now.
5 months ago the coolant was green - now fairly dirty -in thermo housing the alloy is black - trouble is I don't do long journeys currently so the bus does'nt get the oportunity to prove itself - I did note small amount of fluid/oil around the viscous bearing - having said that with the engine cover up on a motorway today the viscous did perform - even bringing it down to 91c once off (having the cover up altered airflow and allowed radiant heat to disperse)
Currently,(summer uk) lowest I see is 97c (rare)but only when idling for a while and 98c when very light driving but it averages 99-100c town driving.
As the 3L engine is very rare in this country, the last thing I want to do (or could afford to do) is contribute to its demise.
I am concerned about trusting it at these temps.
I dont know what an unsafe temp is for these iron engines or how a crossflow rad works - if anyone can enlighten me please do - I will follow all suggestions (cheapest 1st)

- (#9824) chris turner, 21 Jul 03 16:44

easy. In an old-fashioned rad, the tanks are top and bottom, and the top tank is generally the hot end. Coolant flows vertically, filler cap at top.

The cross- flow rad (as the name suggests) has the tanks at left and right, the coolant flowing left to right. There will either be a seperate expansion tank, or it'll be built on to one of the ends...

The change is mostly made for packaging reasons, the couple of inches saved top and bottom reduced bonnet height. There's also an efficiency increase IIRC

- (#9825) david miller, 22 Jul 03 1:07

Sorry to bother you again chaps but its me again re; my overheating. I had my Townie 2.0 EFI checked by my local Garage and he said that the viscouse fan had failed which was causing it to overheat so I had it replaced by electric fans which I thought had done the trick until a trip to Glasgow from Liverpool. I had done about 50 miles of fairly easy driving then as the motorway became a little less busy I put on more speed and almost imediatly the temp gauge neddle started to climb. I pulled over on to the hard sholder and checked to see what was wrong and noticed that water was pouring out of the expansion tank as before. I got a lift home by Club Toyota RAC and today took my Townie to another local garage. He checked it out and said he suspects that the radiator is blocked. When the engine is hot the rad is reading 29 degrees C at the bottom and 90 degrees C at the top. Before I go ahead and get the rad recored I want to know if these temps are normal for a Town Ace 2.0 EFI or if they do indicate that the rad is blocked. Can any one recomend a good place in the ST.Helens, Merseyside area that does radiator recores. Thanks.

- (#10105) Bill, 4 Aug 03 16:53

sounds like rad OK...

- (#10106) david miller, 5 Aug 03 1:23

Yes it is the rad. Checked it myself after running the Townie for half an hour and found that the rad core was stone cold. Getting it done next week so hope all will be fine after that as going away on holiday in the Townie in two weeks.

- (#10107) Bill, 7 Aug 03 17:45

Yea...my cars thermostat jumps to high then returns to the average temp every 10 min or so. I thought it might have been from engine overloading however once i turned everything off it stay in the already stated pattern. Anyone know what this may be?

- (#10305) JOhn, 16 Aug 03 13:36

Hello John.
By thermostat I take it you mean temperature gauge?
It does sound like a faulty or sticky thermostat though. You don’t say what type of bus you have, so get a proper Toyota stat. The 4x4 auto Townace’s have a 30 mm opening, I mistakenly replaced mine with an aftermarket stat with only a 25 mm opening, and had much the same problem as you describe.
Hope that helps
Dave Bright

- (#10306) dave Bright, 16 Aug 03 14:17