dave5526 Posted October 1, 2012 Share Posted October 1, 2012 (edited) Hi guys, First post on here and wasn't expecting to be this! I bought my first Supra just over a week ago and drove it back from Warwick (to Shrewsbury), no problems everything seemed to be running smoothly. The only fault I could find when viewing the car was that the heater wasn't getting hot - occasionally lukewarm but mostly just cold. The pipes going into and out of the firewall were getting pretty hot and I checked the little control rod in the passengers footwell after doing a search on here which was fine. The previous owner had replaced the thermostat recently so was fairly certain it wasn't that, and he suggested that the problem was probably caused by a blockage in the heater matrix and that a good flush might sort it. So I emptied the coolant, flushed with a garden hose through the heater matrix both ways and from the radiator filler neck. Also bought a bottle of Holts Speedflush to try and clear if it was a blockage, as the inside of the radiator cap and the inside of the top radiator hose were covered in rust/particles, and the long-ish hose going to the small H-shaped hardpipe by the firewall was very stiff - when I squeezed it it softened up a bit as if it was crusted with something inside. The instructions said to half fill the system, put the Speedlush in, fill the rest of the system and then leave in for 30-40 miles before flushing again and refilling with coolant, so with the flush in the system we took the Supra when we went to the pub yesterday, drove aprox 20 miles with no issues whatsover. On the way to my parents house from the pub the engine started vibrating (could feel it through the seats more than the pedals) a little more than usual but then seemed to stop before we got there - because of the vibrations I was driving very gently so that may have just been masking the problem. Then on the way home from my parents we got less than 2 mins down the road before the engine started really shaking and making quite a bit of noise, the car seemed to be lacking in power and 30 secs later a red warning light with heatwave lines came on. At this point I thought the car was maybe overheating and the dash temp guage wasn't reading right so I pulled over, but the light had already gone off (it was only on for about 5 secs). After a quick search just now it appears it was the CAT overheating light that came on. The engine seemed very hot when I pulled over so I thought maybe I had got an airlock into the cooling system when refilling, although I thought I had bled it pretty well and the temp guage needle was still below normal operating temperature when we pulled over. So we left the car to cool down, got picked up and taken home and then went back to it this morning. Started the engine and it sounded maybe slightly rough on idle, but as soon as I revved it slightly the engine started shaking again and sounds like it is misfiring. I decided to leave it until I had further advice and haven't touched it since so hoping someone has a suggestion as to what to do next? Any idea's what it sounds like the problem could be, or whether it's safe to drive home (approx 3.5 miles on the bypass or 4.5 miles if I avoid the bypass so I can drive slower)? Possible thoughts I've already have are: a) I've got some water where it shouldn't be (spark plug wells?) while flushing the heater matrix - although I had tried to be careful and not get too much water around the engine bay, I was rushing and did spill some a couple of times I think - not vast quantities though b) The speedflush has somehow dislodged some sediment or something that was preventing a leak, so I've now got water getting into the spark plugs or engine that way? c) The other thing which may be of importance is that, in order to get one of the heater hoses off, I had to pull off a small S-shaped hose right above where they go into the firewall, which I had assumed was coolant without bothering to follow the hose - then realised it smelled suspiciously like petrol when it came off! Lesson learned - I replaced the hose ASAP and didn't think much more of it but now wondering if this could have caused an issue with fueling? Not sure that any of these would explain the CAT overheating warning light though, or the fact that the engine seemed very hot when it hadn't even reached operating temperature? Edit - also forgot to mention the previous owner said the car has been decatted if this has any bearing on the CAT overheating light. Any help/suggestions are much appreciated! Edited October 13, 2012 by dave5526 (see edit history) Quote Link to comment Share on other sites More sharing options...
sideexitsupra Posted October 2, 2012 Share Posted October 2, 2012 Your best bet would be to take the car to Chris Wilson on here as he is very local to you. It might cost a couple of quid but at least you will know exactly what needs doing and if he does it, it will be done right. He will also be able to tell you anything else that needs attention too, as he knows these cars inside out. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted October 2, 2012 Share Posted October 2, 2012 My best guess for lumpy idle and loss of power is it's running on 5 cylinders. I could be wrong though. If I'm right, it could be a spark lead to a specific cylinder, or the spark plug. Quote Link to comment Share on other sites More sharing options...
Nic Posted October 2, 2012 Share Posted October 2, 2012 The cat overheating light (and other warning lights on that side) can illuminate if there's an alternator/earth issue, I'd check the condition of the crank pulley, if it's delaminated and slipping this could be the cause. The engine shaking sounds like it wasn't firing on all cylinders most likely caused by the coolant in the plug holes, you'll need to find the source of the leak then use a compressed airline to blow out the coolant and check all the HT leads are secure. As said you're close to Chris Wilson, if you're not sure what you're doing then I would get in contact and get him to sort it for you.. Quote Link to comment Share on other sites More sharing options...
st1989 Posted October 2, 2012 Share Posted October 2, 2012 Not too sure about the lights but i blew a coolant hose at one point and ended up with water on coils, made engine run rough. So would start by drying up coil area as best as possible, an air compressor would be best to blow out water before removing plugs then clean spark plugs etc and start the car and see how it runs. You could always do a compressions test while you have plugs out just to make sure the head gasket is okay. Best to have the supra on a hill/ramp when filling the coolant as the heater matrix hoses are at the top of the engine, lets the air out easier when bleeding the system. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 2, 2012 Share Posted October 2, 2012 Water in the plug wells is my bet causing a missfire seeing as it sounds like you had the matrix inlet and outlet pipes off to do a flush Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 2, 2012 Share Posted October 2, 2012 The water in the plug wells seems most obvious considering you were doing work around that area. The unburnt fuel due to the misfire can combust in the exhaust and overheat the CAT. It could be something to do with your ignition timing, though. Very retarded ignition will cause a huge lack of power (to the point that it won't rev past mid-revs even in neutral at WOT), and the combustion continues into the exhaust system, making your manifold glow even at idle. That'll set off the CAT sensor and cause your other symptoms. Check the distributor hasn't somehow slipped/rotated and doesn't show signs of arcing inside the cap. -Ian Quote Link to comment Share on other sites More sharing options...
dave5526 Posted October 3, 2012 Author Share Posted October 3, 2012 Thanks for the replies, got the car back to my parents house (was a bit worried about leaving it where it was, pulled over on a fairly busy road with no houses or anything nearby!), for the first 30 secs or so of very gentle driving it didn't seem too bad but got worse the longer I drove it, struggled to get up a slight hill and by the time I got to my parents house, which only took about 2mins total, the CAT overheating light was back on and didn't go off this time. It does seem to hit a bit of a wall just over 3k RPM. I have a bit of time to look at it tonight so going to check the black plug above the heater matrix pipes as I remember I had to remove this and the bracket it's attached to and it did have an earth on the bolt behind it, so going to check the earth is good and that the plug hasn't got wet somehow (although I'd be shocked if one wet connection is causing the engine to behave as badly as it is!). Will also check the dizzy, I had actually already ordered a new dizzy, rotor arm and spark plugs to replace anyway as I wasn't sure when they were last done. I was also going to replace the HT leads but found they are about £200 for magnecors and I can't find an alternative other than genuine Toyota, which I expect will be just as expensive, so was going to check the condition of them before shelling out. If no joy with the dizzy etc I'll check the spark plug wells, which looks far more laborious than it is on my MR2 - I notice it involves taking the throttle body off and the gasket is a non re-usable part - any ideas where to get one other than Toyota? I wasn't aware there was a Supra specialist so close so if I can't find the problem myself I'll get in contact with Chris Wilson, good to know there's an expert so close by and may actually get it booked in for a general check over anyway for peace of mind, even if I get it running smoothly again. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 3, 2012 Share Posted October 3, 2012 Genuine Toyota are Leads are £123.74 Dizzy cap is £22.77 Rotor arm £9.80 All plus vat but less whatever discount you can get, 10-20 % if your cheeky enough Quote Link to comment Share on other sites More sharing options...
LOGIE Posted October 3, 2012 Share Posted October 3, 2012 Genuine Toyota are Leads are £123.74 Dizzy cap is £22.77 Rotor arm £9.80 All plus vat but less whatever discount you can get, 10-20 % if your cheeky enough Plus if your doing this you might want to fit Iridium spark plugs as its a pita changing them so might as well do them seeing as you have the throttle body etc off anyway. Dnk advised me on this a few years ago. Definately worth doing. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 3, 2012 Share Posted October 3, 2012 Plus if your doing this you might want to fit Iridium spark plugs as its a pita changing them so might as well do them seeing as you have the throttle body etc off anyway. Dnk advised me on this a few years ago. Definately worth doing. Makes sense to me http://www.sparkplugs.co.uk £5.90 each or search ebay/amazon Quote Link to comment Share on other sites More sharing options...
David P Posted October 3, 2012 Share Posted October 3, 2012 I'm sure you will find that water in the plug-well is the issue. If you want a set of after-market leads at the right price, I noticed that Keron has a clean trendy used set. http://www.mkivsupra.net/vbb/member.php?676-keron Quote Link to comment Share on other sites More sharing options...
Shane Posted October 3, 2012 Share Posted October 3, 2012 Had simular issues on my NA when I was flushing the heater matrix and was due to water down in the plug wells. Also, if the previous owner is right and the car has been de-catted, its possible the cat temp sensor wire has not been tied out of the way and has melted all over the decat or adjacent exhaust pipe. This was exactly what happened to a Honda my missus had a year or so ago and when the conductor touched the decat the light came on. A cable tie was all that was needed. Its worth taking your time and checking the water level over and over when you refill as some people have experienced air locking problems on the NA, CW says he has never had a problem but I have and have read others experience this too. Get the front up nice and high so the filler cap is higher than any other point of the water system and let it cool and keep topping up. Good luck, and welcome by the way. Quote Link to comment Share on other sites More sharing options...
Scooter Posted October 3, 2012 Share Posted October 3, 2012 (edited) I'll check the spark plug wells, which looks far more laborious than it is on my MR2 - I notice it involves taking the throttle body off and the gasket is a non re-usable part - any ideas where to get one other than Toyota? It's probably 'best practice' but i've reused before fine............you need to undo the 'y' section of the inlet manifold right of centre when looking from the front, 4 12mm bolts up top x2 12mm bolts below (from memory) I'll pop up a thread that shows pics in a link in a sec.....if you take off a couple of rubber vacuum pipes you can move the hardward out of the way enough to get to the plugs and you don't need to remove the throttle cable etc. See post 26 here in the link below http://www.mkivsupra.net/vbb/showthread.php?4262-S-Plugs/page2&highlight=plugs Edited October 3, 2012 by Scooter (see edit history) Quote Link to comment Share on other sites More sharing options...
David P Posted October 3, 2012 Share Posted October 3, 2012 Treat the gasket kindly and it will treat you kindly too. I had the one on mine on and off more often than hot dinners at times and never a problem. Quote Link to comment Share on other sites More sharing options...
dave5526 Posted October 4, 2012 Author Share Posted October 4, 2012 Thanks for all the helpful pointers, didn't get chance to do any last night and my parents neighbours probably aren't too happy about having it parked in front of their house so decided to get the RAC out tonight to recover it home - then have a proper look when I have it back on my drive over the weekend. Already have a new dizzy cap, rotor arm, NGK iridium spark plugs and now magnecor leads and a new air filter on the way to fit while I have it all off and the car had an oil change a couple of weeks ago so at least this will rule out all the minor service items (bar a fuel filter I suppose) if water in the plug wells doesn't turn out to be the issue. Does nobody think the fuel hose I pulled off to access the heater hoses would cause a problem? I wasn't sure if it could have messed up the system somehow, I always though fuel systems were pressurized but it didn't squirt fuel everywhere when I pulled it off. Quote Link to comment Share on other sites More sharing options...
David P Posted October 4, 2012 Share Posted October 4, 2012 It is the fuel return pipe to the tank. Quote Link to comment Share on other sites More sharing options...
dave5526 Posted October 6, 2012 Author Share Posted October 6, 2012 Update: RAC got the car home on Thursday, the tech who came out agreed that it sounded like it was misfiring on at least 2 cylinders and suspected it was either the spark plugs or leads, I told him I'd been flushing the heater matrix and that I thought there could be water in there but he wasn't too concerned, he thought it more likely the plugs or leads were just in need of replacement. This morning I pulled the dizzy cap and rotor arm to find both were in pretty poor condition so I will be replacing those when I put it all back together. Also pulled the throttle body, which wasn't as bad as expected, and removed the leads to find water in chambers 3-6 (assuming the one nearest the cambelt is 1)! The 5 and 6 were the worst nearest the heater hoses so I suspect it was my flushing that did it, I have a clean cloth in each chamber now trying to soak up as much water as possible and then since it's so sunny and warm I'm going to leave them to air dry for a while (the leads were dry within minutes so shouldn't take long to dry out properly). Then going to replace the spark plugs with the new iridium's and fit the new leads, dizzy cap and rotor arm when the leads arrive. My question is - I've read there is a hose that can split and leak into the spark plug chambers, can anyone tell me where this is and if there is any way to check this while I've got access? I dont want to fit all the new parts only to find the chambers fill up with water as soon as I drive it again! The heater hose that goes down the back of the engine is quite wet at the lower end and the back of the engine is a bit wet/oily which makes me think there may be a small leak somewhere? I've tried the search function but doesn't seem to be working for me, comes up with no results. So I searched for "oil" as a test and it came up with nothing - I can't believe there isn't a single post with the word "oil" on here! Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 6, 2012 Share Posted October 6, 2012 Have you not got a foot pump or bicycle pump to blow the water away with Quote Link to comment Share on other sites More sharing options...
dave5526 Posted October 6, 2012 Author Share Posted October 6, 2012 I have a 12v electric air compressor but it's pitifully low power and didn't seem to do anything - my own lungs would do better. But going to try a hair dryer when I remove the cloths after lunch which should help. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 6, 2012 Share Posted October 6, 2012 Does the Mrs know : Quote Link to comment Share on other sites More sharing options...
dave5526 Posted October 6, 2012 Author Share Posted October 6, 2012 Lol - not yet - and hopefully she never will! Quote Link to comment Share on other sites More sharing options...
DodgyRog Posted October 6, 2012 Share Posted October 6, 2012 If there is any sign of moisture in the plug wells, then it is very likely to cause a misfire, it's a massive pain on the N/A's............................never let any amount of water/fluid anywhere near the top of the engine If you seem to have a 2 cylinder misfire, run the engine and remove one lead until you find one that doesn't make a difference, then at least you know which one is not firing Quote Link to comment Share on other sites More sharing options...
listy Posted October 6, 2012 Share Posted October 6, 2012 I've tried the search function but doesn't seem to be working for me, comes up with no results. So I searched for "oil" as a test and it came up with nothing - I can't believe there isn't a single post with the word "oil" on here! The search function will discount any commonly used words. So things like "oil" "spark" etc will be ignored. Quote Link to comment Share on other sites More sharing options...
Nic Posted October 6, 2012 Share Posted October 6, 2012 The search function will discount any commonly used words. So things like "oil" "spark" etc will be ignored. It won't accept 'oil' because it's a 3 letter word, 4 letter words or more only. Quote Link to comment Share on other sites More sharing options...
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