mysterious water loss

callum

Well-Known Member
Apr 27, 2010
202
4
38
Edinburgh
Hi,

first post here, have posted over on the other forum, but the restrictions on posting were a bit annoying, so hopefully here will be a bit easier. Vehicle is a 1991 hdj81.

Anyway, i'm suffering a bit of coolant loss, about 500ml every 150 miles or so. Its not causing any problems, temp is still dead centre, no smoke on startup, oil looks fine and no deposits in the header (well actually all the coolant just disappears from the header if i'm being honest). to be honest aside from this the car is running great and providing a surprising economy to boot.

I've only had the car a few months, but i'm pretty sure that this is not normal. Doesn't seem to have any of the symptoms of head gasket leakage, so i think it must be a leak in the system somewhere under pressure. is there a usual culprit for this, like the heater system?

Unfortunately there are no visible drips anywhere or no traces of leakage i can see. i think this may be a job for a garage with some pressure testing equipment to be honest, but if i can sort it myself then all the better.

thanks for your help

callum
 

Crispin

Administrator
Staff member
Guru
I am in great_britain
Feb 24, 2010
5,970
576
113
springs, gauteng
All I can offer is a welcome. I'm sure one of the 80 gurus will be along shortly.

I am sure on of them had leaky rear(?) heater matrix pipes which were corroded.
 
Don't like the adverts? Remove them by becoming a supporting member.   Click here

Paul

Well-Known Member
I am in england
Mar 1, 2010
2,465
42
48
Southampton
Garage
Heater matrix pipes are soon to be blocked off on mine as very badly corroded, will do a write up.

Have you run the heaters at full? Maybe the system was filled but not bled through properly?
 

Andrew Prince

Well-Known Member
Feb 23, 2010
2,232
13
38
Joburg, sunny South Africa
Hi Callum, and welcome!

I would second the suggestions posted above. Do not rely on the temp guage as they are not the most sensitive and it could be too late by the time the guage actually moves.

A couple of further suggestions:
- try getting someone else to start it from cold after it's been left overnight, while you watch the exhaust closely. You're on the look-out for a decent amount of white smoke/steam coming out. A little is ok (condensation in exhaust) but more than a few wisps could indicate a leaking head gasket or worse. You could get the coolant tested for traces of exhaust gases too.
- Start up the truck with the rad cap off and watch (not too close if the truck is hot!!). If coolant comes splashing out, then gases are pressurising the system and you have a gasket leak or crack.
- Have a thorough look underneath the radiator, engine and heater pipes running to the rear heaters. Look for any signs of dampness. If you have a modest leak, the coolant could run along the pipes and not show up as a puddle under the car (although anything more than a small leak will form a puddle). It could be that under pressure, the leak is more severe, as you indicated. Also have a look around the water pump for signs of leaking.

BTW are you running the standard red Toyota coolant? What are you topping it up with?

Good luck!
 

callum

Well-Known Member
Apr 27, 2010
202
4
38
Edinburgh
wow, some fast responses there.

Sounds like i have a few things to check before visiting the garage. As it happens, the rad cap looks like an ebay special. I can't see them on ebay now, but it looks like something that would be marketed towards an import integra owner.

is it best to get hold of one from the toyota dealer rather than motor factors etc?
 

callum

Well-Known Member
Apr 27, 2010
202
4
38
Edinburgh
just topping it up with a halfords coolant mix with water at the moment.

what is the toyota red coolant? i've seen it mentioned on ih8mud, but i've never had to use a manufacturer specific coolant in a car before.
 

Andrew Prince

Well-Known Member
Feb 23, 2010
2,232
13
38
Joburg, sunny South Africa
callum said:
is it best to get hold of one from the toyota dealer rather than motor factors etc?
Yes! You don't say where you're based but many of the main dealers are not too helpful when it comes to imports and act like they were made in a different factory to the UK-spec ones :roll:
I think the part no. for the rad cap for your model is 16401-71010 - it might be useful to have the part number handy if your friendly Toyota parts man starts playing dumb! ;)
 

Andrew Prince

Well-Known Member
Feb 23, 2010
2,232
13
38
Joburg, sunny South Africa
callum said:
what is the toyota red coolant? i've seen it mentioned on ih8mud, but i've never had to use a manufacturer specific coolant in a car before.
No doubt it comes from some general coolant source but made to Toyota specs. Pick some up while you're getting your new rad cap :cool:
 

Gary Stockton

Super Moderator
Supporter
I am in zimbabwe
Sep 10, 2012
3,924
38
48
Edinburgh
Garage
It's also got some magic muti in it to help lubricate and prevent rust, especially for those with oil coolers in the cooling system, like on the 90s.

Cheers
 

callum

Well-Known Member
Apr 27, 2010
202
4
38
Edinburgh
actually the dealer i have used has been ok. (maybe i should add my location to my profile)

granted they're not quite as good as a land rover parts desk, but they had no problem with an import. i had to get a new seatbelt assembly following an exploding reel spring and they were able to get it in for the next day. Was only £50 as well, i was expecting to have to fork out much more.

need to pay them a visit to get a set of con rod bolts for changing the beb's so will get a rad cap at the same time and see how much of a premium genuine parts coolant commands.

thanks for the help, much appreciated.

callum
 

tomrichardson

Active Member
i had a mysterious coolant leak for a while. turned out to be a leak on the top hose where it goes into the block. it didin't leak when cold or when hot, but there seemed to be a point in temperature where the ally hadn't expanded enough with the hose and it leaked. took me bloody ages to find it, but worth checking all pipe connections. no trace of staining from the coolant was present either.
 

Bat21

Well-Known Member
Supporter
I am in morocco
Feb 24, 2010
1,902
138
63
Shropshirington
Hi Callum, welcome to the more friendly site ;)

I have the exact same model as you, Jan 92 HDJ81 and had exactly the same problem.

It took me months to find the problem, there were loads of scary suggestions as to what it might be and to be honest I was fearing the worst.

How I discovered what was causing the problem was quite bizarre. I was standing by my truck talking to a mate one day when suddenly she (not my mate :D) decided to take a whizz. The engine hadn't even been running that day and yet all of a sudden she deposited a puddle right before our eyes :o

It turned out that there was a tiny hole in the rad which up until that moment proved impossible to find :?

What I would suggest is, while we have this dry spell, get under your truck and check for any damp patches around the rad area. As we have had no rain for quite some time now it should be bone dry... if it isn't then you have found your problem.

If you are anywhere near Shropshire you're more than welcome to pop over and I'll have a look.

Paul

PS looks like you have the JDM import too.. the same as mine.
 

kirk ross

New Member
Mar 15, 2010
2
0
1
There are some pipes that run from just behind the engine under the vehicle to the heaters for the rear seats. The fittings are made of poor quality metal and can corrode and split causing coolant loss. This occurred on my import so as I had never used the rear heaters I sealed the flow and return pipes using 15mm copper pipe with soldered blanking caps. The pipework is easy to access just to the left of the block near the bulkhead. I have had no trouble since.


Regards Kirk
 

adrianr

Well-Known Member
Mar 4, 2010
1,638
9
38
Off in the trees, again
An alternative solution should you wish to keep the rear heater is to run some rubber hose from the engine bay back to the rear heater - along chassis rail and bypass the metal pipes.
 
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock    No Thanks