Homer Posted March 21, 2009 Share Posted March 21, 2009 Hi folks, now the nice weather has arrived it's time to do the final few jobs on the car and get it back on the road. So, going back to one of the issues I had before (no heat in the cabin), have done some further checks and now need some advice. The matrix was okay, I connected up a hosepipe to the inlet and slowly let some water pass through it to give it a flush. There was a bit of air in it, and some very rusty looking water, but after flushing clear water flowed through it with no leaks. Connected it all back up and topped up the pipes at the back as best I could and ran it again.. now, there is a little heat coming into the cabin, however: The 'in' pipe to the heater matrix is getting up to full temp The 'out' pipe is cool The interior heater is giving out a bit of heat, but not like it should The 'in' to the water pump is up to full temp (very hot) The outlet from the water pump to the bottom of the rad is stone cold. The upper rad hose gets warm, but it seems no water is circulating through the rad. The water temp gauge goes up faster than is normal, and sits past the half way point once idling for 5 mins. So, with this I think the heater matrix and air locks are not the issue. Is the water pump Shot? Could this be a thermostat issue (not sure how these work) Could there be another issue that making the water not circulate through the engine? Quote Link to comment Share on other sites More sharing options...
bignum Posted March 21, 2009 Share Posted March 21, 2009 It could be either the water pump or the stat at fault, most likely the stat stuck closed, i think you can take the stat out quite easily to have a butchers. Quote Link to comment Share on other sites More sharing options...
SupraTRD83 Posted March 21, 2009 Share Posted March 21, 2009 I found it was the Water Pump on mine when it oerheated, there should be a leak if its that, check the water levels, either that or the rad, i have a used rad if you need for cheap, pm Quote Link to comment Share on other sites More sharing options...
SteveR Posted March 21, 2009 Share Posted March 21, 2009 Does the rad/top hose get hot when the engine it up to temp? Quote Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2009 Author Share Posted March 21, 2009 It could be either the water pump or the stat at fault, most likely the stat stuck closed, i think you can take the stat out quite easily to have a butchers. Thanks Si, I don't even know where the stat is, but will take a look tomorrow. I found it was the Water Pump on mine when it oerheated, there should be a leak if its that, check the water levels, either that or the rad, i have a used rad if you need for cheap, pm The water levels are good and theres no leaks. The rad is out of a low mileage 6spd, it's the larger one of the two Supra rads so should be fine with the NA. Does the rad/top hose get hot when the engine it up to temp? Not really, it only gets "warm" after the engine is stopped. The engine end of the water pipe is hot, but the rad end is near cold. Again it hints that no water is circulating. Is the water supposed to circulate around the system (and rad) even when the engine is cold? I'm not clear on what effect a dodgy thermostat would have on the car. Quote Link to comment Share on other sites More sharing options...
SteveR Posted March 21, 2009 Share Posted March 21, 2009 Is the water supposed to circulate around the system (and rad) even when the engine is cold? I'm not clear on what effect a dodgy thermostat would have on the car. No I don't think so. From memory the top pipe will stay cold until the momet the thermostat opens, and then all of a sudden it gets hot very quickly (especially if you've got a rigid metal pipe!) Sound like it will be the cheaper option of it being the thermostat rather than the pump. Quote Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2009 Author Share Posted March 21, 2009 Sound like it will be the cheaper option of it being the thermostat rather than the pump. Thanks Steve. I'd prefer this to be a bad stat than a pump, swapping those is a pita! Will give the stat a once over tomorrow, once I find out where it is (thank god for the service manuals ) Quote Link to comment Share on other sites More sharing options...
SimonB Posted March 21, 2009 Share Posted March 21, 2009 (edited) Thanks Steve. I'd prefer this to be a bad stat than a pump, swapping those is a pita! Will give the stat a once over tomorrow, once I find out where it is (thank god for the service manuals ) It's in the bottom pipe off the water pump, the one that connects to the rad bottom hose. It stops water going through the rad when the engine is cold, but water should still circulate round the engine and heater matrix I think. Although actually thinking about it I'm not sure! If the thermostat is stuck closed it would make the engine overheat as the rad is effectively not being used. If stuck open it would take ages for the engine to get up to temp. Edited March 21, 2009 by SimonB (see edit history) Quote Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2009 Author Share Posted March 21, 2009 It's in the bottom pipe off the water pump, the one that connects to the rad bottom hose. It stops water going through the rad when the engine is cold, but water should still circulate round the engine and heater matrix I think. Although actually thinking about it I'm not sure! If the thermostat is stuck closed it would make the engine overheat as the rad is effectively not being used. If stuck open it would take ages for the engine to get up to temp. Thanks Simon, a broken pump does seem to be the issue then. The engine water temps heats up far quicker than it should which would indicate no pump working. The rad has no flow through it, but neither does the heater matrix or some of the other items like the heater line to the throttle body. I'll check the thermostat anyway tomorrow and see if it's frozen up, but from what you've said it does appear to be a broken pump. Bugger, might just as well rip this lump out and fit something else. Quote Link to comment Share on other sites More sharing options...
dani_r Posted March 22, 2009 Share Posted March 22, 2009 I'd check the thermostat first for sure! My Daihatsu HiJet van was overheating like crazy, i ripped the thermostat out and tested it, found to not be opening when it should (at 83 degress C i think) so bought a new one, now it doesn't overheat! Troubleshooting is a PITA, but I always like to start with the cheaper options before buying expensive parts Hope you get this sorted Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 22, 2009 Share Posted March 22, 2009 Put in a new genuine Toyota stat and with any luck at all it should be fine. Otherwise look to having the rad flow tested, it may be bunged up (they won't "un-bung" don't bother trying, just buy a new rad). Quote Link to comment Share on other sites More sharing options...
Homer Posted March 22, 2009 Author Share Posted March 22, 2009 Thanks again for the replies, great feedback! I didn't get chance to pull out the thermostat today (will wait until I can get a replacement as well), but did look at the service manual and now realise that it's location might well cause the issues the car has. Chris, thanks. Is a genuine one really needed? They're ridiculously expensive at £70 or so, it's only a thermostat! The rad 'appears' to be fine, the flow through it is very good and no leaks. I connected up a hose pipe to the bottom end and water was flowing freely out the top. Quote Link to comment Share on other sites More sharing options...
bignum Posted March 23, 2009 Share Posted March 23, 2009 You could take the stat out and run the car to see if it solves the problem, james never had a stat in the 2.9 cosworth and never had a problem. Quote Link to comment Share on other sites More sharing options...
Scott Posted March 23, 2009 Share Posted March 23, 2009 Am i right in saying the stat is only there to get the engine up to temperature quicker? As a test you could take it out and plug it up to see if it runs better. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 23, 2009 Share Posted March 23, 2009 I always prefer genuine stats, I have only ever had issues with new stats when they are pattern parts. I think I have a genuine one knocking about from when a customer wanted a cooler race stat fitting. I would sell for a lot less than 70 quid. You could test with no stat, but they do more than control temp, they also control flow. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted March 23, 2009 Share Posted March 23, 2009 I dare say that if you where to check, a lot of "genuine" Toyota parts, and many other's, are made by a third party manufacture, it galls me that an item can come off the same production line and then be sold for six times more because it has a "name" Quote Link to comment Share on other sites More sharing options...
Guest banjo_bob Posted March 23, 2009 Share Posted March 23, 2009 Chris, thanks. Is a genuine one really needed? They're ridiculously expensive at £70 or so, it's only a thermostat! I think you're getting confused with something else, they're only about £15 from Toyota. Part number - 90916 03093 Used on many, many different Toyotas Quote Link to comment Share on other sites More sharing options...
Homer Posted March 23, 2009 Author Share Posted March 23, 2009 Thanks again all. The Toyota price was going off previous prices quoted on here, but will give the local place a try tomorrow. The site Tricky sent listed them for £11, which is a little more sensible Good call on running it without the stat, will give that a go tomorrow provided I get time. It won't be like that permanently, but should at least confirm if that stat was faulty. Quote Link to comment Share on other sites More sharing options...
Homer Posted March 24, 2009 Author Share Posted March 24, 2009 Removed the stat today and ran the car again. There's now water curculating through the rad, it's getting nice and hot. Also the engine is not overheating any more, idling it didn't even get to full temp after 15 minutes However, still very little heat in the cabin and have the same issue with the pipes to and from the matrix, one is VERY hot, the other is only slightly warm. Guess I need to get it to a garage to use the suction method to draw out any air locks. Right PITA when the car has no tax or MOT! BTW, new stat was £14 from toyota, and £5 for the seal (!) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 24, 2009 Share Posted March 24, 2009 They don't suffer from air locks and no special bleeding is needed. are you sure water is circulating through the matrix? Do they have a water control valve, I can't remember, I avoid matrix changes!! If so it may not be opening properly, post up the heater stuff from the parts CD and I'll have a look if you want. Quote Link to comment Share on other sites More sharing options...
Homer Posted March 24, 2009 Author Share Posted March 24, 2009 A few days ago I remove both pipes to to the matrix (the two at the back of the engine bay), attached a hose pipe to the 'in' pipe and ran water through it at low pressure, it seemed to be flowing though fine, even with just a tricky of water from the hose pipe. Looking on EPC, there does seem to be a valve on top of the heater matrix, I wonder if that might be the problem.. When turning the heater from hot to cold and back again I can hear a something operating in the matrix area and had assumed all was well with that. The car had all sorts of electrical issues inside due to some cut looms, and some of the climate control buttons don't work either. Hope it's not the matrix, not sure I can face taking this car apart again! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 24, 2009 Share Posted March 24, 2009 Yes, it's got at least one water flow control valve. If that, or its control, are up the spout it could easily cause a loss of heat to the interior. Quote Link to comment Share on other sites More sharing options...
Homer Posted March 24, 2009 Author Share Posted March 24, 2009 Yes, it's got at least one water flow control valve. If that, or its control, are up the spout it could easily cause a loss of heat to the interior. Thanks Chris. I just got off the phone from Gav who happened to have an entire heater system in his garage, it seems there are two servos on the heater matrix, so potentially one of them is not operatoring (prime suspect being the one in the picture above), it would explain the issue for sure. The car has been sat with no water in it for ~4 years so that servo could well have frozen up. If I don't make any progress tomorrow it looks like the heater matrix is coming out... might as well replace the dodgy dash loom at the same time. Oh fun! Quote Link to comment Share on other sites More sharing options...
bens747 Posted April 6, 2009 Share Posted April 6, 2009 Driving today and noticed the temp gauge had gone right up and then it dropped down and went up again quite quickly. Got back home and the overflow tank was bubbling. Plenty of water in there. Could it be the thermostat. Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
Scott Posted April 6, 2009 Share Posted April 6, 2009 Driving today and noticed the temp gauge had gone right up and then it dropped down and went up again quite quickly. Got back home and the overflow tank was bubbling. Plenty of water in there. Could it be the thermostat. Any help would be appreciated. Have you recently had the coolant changed? Sounds a little bit like it hasn't been bled properly so the air locks are making their way round the system. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.