Nearly had to walk back . . .(long) The background: On the way to Berri, I had Jack (ZXTT-1) aboard as PSA. Now, Jack had his PDA with him, with a mini-conzult program. He normally isn't able to play with the thing, as when it's fitted to his car, he can't easily change the setting ('cause he's driving, see!). We hooked it up to the computer port and monitored various parameters on the way. Jack had a ball playing with the settings while in the LH seat. We monitored engine temps (water, oil, fuel), pressures (oil, fuel), and speed (comparing ECU signals with speedo reading... nice to know my speedo reads 2km high at 60kph, and 4km high at 100 (ie speedo=100, actual speed=96)). Also switched in the GPS program to show speed, but it was so bloody annoying: "In 200 meters, turn back!" The f'in thing was lost most of the time, but I think that was something to do with the way Jack was using it. Anyway, engine temp on the way was fairly steady on 84-85 (no air-con), which is good. Weekend ensued, with some washing and polishing, and drag-racing. Then to Adelaide to see the Old Mum. Jack stayed with friends, and we met up again on Tuesday morning to travel back to Melbourne. PDA was hooked up again. Out of Adelaide on the Eastern Freeway, through the tunnel and into the hills. Aircon ON (it was already 32 degrees outside). Jack says: "Do you know that your engine temp is 103?" I immediately check OEM guage, which is reading half-way, like it always does. TWD is disconnected (destroyed by recent theft of radio) so no warning there. Panic stations - Aircon goes to OFF, heater goes to ON, heater fan goes to 4 (highest setting), windows go down (... remember, it's 32 outside), overdrive goes to OFF to speed up engine fan, prayers go to the "God of my choice". Still travelling up-hill! Temp slowly comes down to 96. TGFT! We can live with 96 for a while! We discussed turning back to Adelaide (2 airfares would be insignificant compared to the cost of an overheated engine repair), but decided to press on. Hills go flat but the engine temperature never went below 95 for the rest of the trip! Considerations: Well, we talked about it, and I decide that it could only be one of several things causing the problem. Coolant loss: dismissed, because when the stress was taken off the system, the temps dropped - they would have stayed high or kept climbing if there was inadequate coolant. When checked the next morning, the coolant level was still up to the neck where the cap fits. Airflow/coolant flow - Possible! No obvious blockages to the airflow, so that's out. Rebuilt radiator (thanks, Mark) fitted a week prior, so no worries there. Blocked flow through the engine? Possible. What would cause that? Ah! Thermostat! Resolution: Back in Melbourne, off comes the plenum. All the small hoses showed signs of leakage (coolant crystallising at the ends), all blown up like miniature balloons in the middle, one with an internal split almost all the way through. Bypassed. Heater hard-pipe which fits in to the rear of the drivers-side head - showing signs of corrosion. Cut and rewelded. Engine coolant flow. Flush shows no obstruction. Thermostat removed and tested. Farked! New thermostat fitted. It has to be stated here that when I bought the car 70K km ago, I had the 100K km service done, with new OEM waterpump, but the original thermostat refitted, 'cause it was working as expected. Big mistake! Transmission cooler fitted. My lovely Zed off the road for 4 days! Lesson: Do NOT believe the readings you get from the OEM temperature gauge! I know we are aware that they are not all that reliable, but, honestly, they are just CRAP! They seem to have only three reading - OFF/OPERATING/TOO LATE! The gauge did not move off the NORMAL setting all through this drama. Fit an after-market gauge NOW!
lol or buy a PDA! Glad it worked out ok Doug. I had the same problem in Jan. It definately is a fault. I found the OEM guage didn't move until around 110.
good stuff dougy... getting it sorted out I mean... But why you complaining about 32 degree heat and no aircon?? I do it all the time lol!! thats what windows and targa roofs are for... C'mon, enjoy the summer..... dont hide from it.. Cheers
