Guys, Took out my '86 328 for a spirited drive and noticed the temp reach 250F. I pulled over and coolant was gushing below the engine out of the reservoir overflow hose outlet. No other coolant leaks anywhere and I just bled the air of the cooling system before the drive. I also verified my water pump to be functioning okay. Coolant level was 2" below the top of the reservoir as prescribed. Once the engine had cooled down to 195F I decided to drive it back and noticed that sometimes the temp would approach the high zone at 240-250F then suddenly drop back down to 185-195F while I am cruising. Once I am in stop-and-go traffic, the temp goes back up to 250F. Also, after I shut down the engine to cool it off, I notice that it will not start again until I let the temperature go down below 195F. The engine will just keep cranking but not start if the temp is above 195F. Once I let the temp drop below 195, she starts right up. Am I on the right track if I chase the following suspects: 1) Thermostat needs replacing? 2) Check the thermo-time switch? (Isn't this somehow physically connected between the coolant and the starting mechanism?) Any help would be appreciated.
Check cooling fans should come on at 195 and drop out at about 180. Thermostat sounds like its shot, they tend to fall apart. Thermo switch is not your problem.
Saw something similar last year & I'd suspect the expansion tank cap to start with. Weak cap, unable to hold pressure = coolant loss while you are driving which you obviously don't see. Leads to big airlocks in the system leads to wild fluctuations in temperature as you described as airlocks pass through the engine. There may appear to be coolant in the tank but that doesn't mean there arn't also big airlocks & generally a lack of coolant in the system. Lots of garages have cap testers so see if you can get it tested - or just go & buy a generic 1.1 bar cap that fits. You've definitly lost some coolant so to refill the system open the heater valves & jack up the rear of the car as high as you can. Bleed air from radiator & thermostat housing. Then start engine with expansion tank cap off. Run for a minute or two & then turn off, re-bleed from radiator and T'stat housing. Add coolant as required. Once you are sure you have all the air out then put the cap on & take it for a run. Make sure you are seeing heat coming from the heaters. If you don't then there is an airlock in there. Liklihood is they will suddenly start working as the airlock clears at which point you'll need to rebleed the system to get the air out - probably from the radiator. Signs of a failed thermostat are more likely that the engine takes a long time time to reach anywhere near operating (water) temp & then once it does the temperature varies a fair bit & will only climb towards normal in traffic. On the open road you might see water temps of under 140. This sort of behaviour is caused by a weak spring on the Stat - stat opens up fine & in fact really too fast & too far & then doesn't close again because the spring is shot. If everything is working right then water temp should always be pretty stable & only climb a bit in traffic. Your fans should cut in at around 195 so check that's working too. Occasionally you might get a sticky thermostat in which case your engine will just boil or alternatively it will get very hot & then suddenly cool down as the stat unsticks & opens. It will only do this once in a heat cycle though - once its opened then you'd expect some stability, not yo-yoing temps. Last possible culprit could be a water pump but you might well hear that if it was shot. My bet is on the expansion tank cap. They don't last more than 3 or 4 years at best. Your cap is weak which led to coolant loss which led to air in the system leading to weird temperature spikes. Change the cap, refill the system & you should be good to go with luck. FWIW I replaced the T'stat on my 328 last year. It now runs at around 170 (the second mark on the gauge) & the temperature is pretty much rock solid no matter what I do with it unless I'm in traffic where it will climb to 190 & then the fans cut in & drop it back to 170 pretty quickly.
Thnx for the suggestions. After the engine cooled I noticed a few things. The reservoir was bone-dry and much of the coolant in the engine was also gone. It took 2 gallons of 50/50 coolant to top it back off. Also I also saw that I have a 0.9bar cap, therefore I will take the advice and change that to 1.1bar. I am still perplexed as to why the engine would not restart after I shut it down after the engine reached very hi-temp. I have not started the car yet and I am hoping that running it momentarily above 250F did not destroy anything! I am also afraid that if I hit a hi-temp again I will have the restarting issue pop up.
Firstly, if your reservoir ran dry, then bleed the system again. Remember to set the heater controls to full "hot" -- air can remain trapped in the heater cores when you bleed in summer if you don't. Air in the system can cause the temperature gauge to briefly swing upwards and then drop again, as an air bubble at the sensor will cause the temp to read higher. If the temperature jumps up and stays there, and then coolent comes boiling out after you shut down, that might be an indication of a head gasket issue: if you're bleeding compression into the coolent, then you could be overpressurizing the cooling system. Boiling temperature increases with pressure -- coolent at well over 212F will remain liquid when pressurized, but will boil if the pressure drops before the temperature. When you say that it "won't start" when it's hot, do you mean that it won't even crank? That might be a separate issue: The battery is behind the radiator. When the battery area gets hot, both the battery cables and the battery posts will expand -- but the cable connector might expand faster, causing a poor connection at the battery. Next time it won't start, you might try wiggling the connector to see if it's gone loose. (Yes, it's a pain to get the cover off) But try bleeding the system a couple of times, top up the coolent, check that the fans come on at 195 (you can do that idling in warm weather), and then go from there.
Sounds like its as I suggested - the issue is the cap allowing coolant to escape. Its possible you might have done some head gasket damage but you'll only find out when you get the cooling system back together properly. With a bit of luck you'll be OK (I'd say your chances are 80:20 that it'll be OK assuming you didn't run too long with low coolant). As for the non starting, could have been some kind of vapour lock in the injection system caused by the whole engine bay being far hotter than normal. Who knows. Best to get the cooling system sorted & then see if the problem re-occurs I.
How did you verify? I 'm not sure how the impeller is attached on the 328 pump. Some press fit ones can come loose on the shaft, especially as the temperature rises.
Great post, Iain! Also, check the little things. I had a newspaper that had gotten sucked up into the radiator of a Corvette that I owned that caused some wierd high-temp issues! Verify that your radiator fans are actually turning, too. Blown fuses, failing relays, debris in the fans, or a bad alternator (not enough amps to spin the fans fast enough) can all cause temp issues that vary with driving speed.
Refilled coolant to normal level and bled as well as I could as suggested. Now will be buying a new cap and test drive. The car started just fine and warmed up to normal temp. No sign of any damage to the engine so far, so I am keeping my fingers crossed that running it in overtemp did not result in any major damage. Will go get 1.1bar cap as soon as I come back from a trip. In the meantime, she will sit and relax a few days! The hard start issue seems to be related to a temp sensor that controls the warm up cycle, but I am still not sure. All I know is that the car now starts out fine. When it was overheated, and probably no coolant circulating in the area of "this" sensor, the temp somehow caused the "no start" situation. The engine would just cycle but never start. I am not sure if it was vapor lock because I must have attempted to start the engine a dozen times while it was cooling down. Once the temp got down to about 195F, she starts right up. Weird.
I suppose it could be the warm up regulator. Its attached to the expansion tank & whilst your engine temp was way high your coolant level was low meaning the tank was possibly cooler than it would normally have been & so the WUR confused the injection system into over fuelling the thing etc etc.... OTOH I still quite favour the vapour lock idea.... Who who knows, and who cares if it works OK at proper operating temps!!! Good luck & keep us posted - its always useful to see what the ultimate resolution to a given problem is. rgds I.
Replaced the radiatior cap with $4 Napa 16-lb cap and so far I have not had any overheating problems. Drained and replaced the radiator fluid, changed the oil (as i ran the old oil on quite hi temp) and so far she runs cool and strong. Even got the chance to lube the throttle cable since I had the oil filter out of the way! She's smooth as butter now!
Glad to hear it. The Napa cap maybe doesn't look quite right (round instead of square?) but I bet it'll last a lot longer! For peace of mind suggest you do a test to make sure your fans are cutting in at 190 as they should. Just leave the car sitting at idle & watch the temp climb till the fans cut in (or not!). If they don't cut in at 190 then your thermoswitch needs replacing. Also, when you say "runs cool" what temp are you seeing on the gauge during normal running? If its much below the second mark (170 ish) then its too cool & you'd have a suspect T'stat. Water temp should stay pretty much planted unless you get into traffic when it will climb to 190 & when the fans should cut in to drop it back to 170. If its moving around a fair bit as you are driving then the T'stat is probably past its best. Oil temp (on the other hand) should be expected to move around a bit depending on how you are driving. Lastly, it'll take longer than you think to get all the air out the system - keep checking the radiator bleed screw every so often I.
Looks like you're okay, congratulations! Just a point to make: Cars with aluminum heads can't run in overheat mode like an American iron job. The heads distort quickly when overheated; the head gasket is the least of your worries in that case. If you ever overheat again, STOP as soon as you realize it. Get a flatbed tow, do not limp home unless you can refill the system and keep it at a reasonable temperature while limping. Ferrari engines in particular are a close tolerence, well balanced machine that is strong, but can't take abuse such as overheating without risking major damage. Ken
Yep, the fans do kick in at around 185-190F as specified. Water temp stays at around 195F on normal runs and spirited runs I would see the temp rise perhaps 10% with the new cap. Definitely feel lucky not seeing (so far) any damage from the hi-temp running, albeit only a short while. No evidence of oil in the coolant nor any white smoke from the exhaust, so perhaps the head gaskets are holding for now...
Gatsby, Your car is old enough that you should think about doing some radiator work. My '76 308 was 15 years old when the radiator became completely clogged up which caused it to heat up in stop and go traffic. I had the choice of letting the dealer do it or do it myself. I did it myself. I removed the radiator and took it to a local radiator shop. They rodded it out, repaired a small leak, repainted it and its been working great ever since. Hint: When I took it in I told them it was out of a Fiat and they charged me only $75. I'm sure if I had told them it was from a Ferrari it would have cost $300.
Car sounds like its running fine BUT..... that's significantly higher than my gauge reads during normal running. The only datapoint I (we) have is that the fans should cut in at around 195 and mine do - but during normal running the temp stays rooted to the second mark on the gauge - about 170 ish. If I really push the thing it will climb so I can just about see the mark to the left side of the needle (i.e. about 5 degrees!). Oil temp on my car will move about much more than water temp based on how I'm driving - as I think it should because there is no T'stat in the oil cooler circuit. My water temp will only climb to 195 in stop-start traffic - i.e when the car is basically stationary. When it gets up there (195) then the fans cut in and they will drop the thing back to 170 ish quite quickly and then turn off. Based on what you've said it would imply that your fans must be running pretty much constantly & if that's the case it sounds like your gauge is reading about right. For me that would also mean your car is running a bit too hot - I don't think the fans should be running pretty much all the time. There would seem to be 4 possible causes for that: a) A bad or incorrect thermostat b) A weak/failing water pump c) A slipping WP belt d) A partially blocked radiator (either internally or externally). The WP & belt should be easy to diagnose so I'd start with changing the Thermostat - sadly not cheap from Ferrari for a 328 but Daniel at Ricambi has some alternative versions (one of which is in my car). Suggest you give him a call & see how much he needs for one. If you change the Stat make sure it has the little air bleed hole in the flange & position this at the highest point - you'll see what I mean if you get in there. Also be careful when you remove the T'stat housing that you don't drop any of the bolts - you are right on top of the cam belts. Lastly drain the block down before removing the old stat so that you don't spill coolant all over your cambelts either. One other thing you could check is that the duct to the oil cooler is clear and attached. Not sure how this might affect water temp but if its come away from the scoop at the front & isn't ducting air to the oil cooler it can't be helping engine cooling generally. I.
Iain, et.al., Took the car out for a long drive in hot weather today and was fine. 45 mins into the drive I drove into town in stop and go traffic and noticed the temp starting to rise above 195. I could hear the fans going and verified that indeed they were blowing when I pulled over. However the temp continued to rise up to 220F as it did a few weeks back. I pulled over and let it cool down- I noticed that it again was shooting coolant off the drain hose despite the 1.1bar cap. Once the car cooled off, I opened the radiator cap and added more coolant and drove again. This time the temp remained around 170F all the way home. I am now trying to chase down this gremlin. Next on my list is rodding out the radiator and changing the thermostat as you guys suggested. -Its really getting tiresome to keep checking the water temp every minute as I drive!
Well it took a while but I finally solved my cooling system issue last week. I now know more about my car's cooling system than ever before. Here's what I found: 1) Opened thermostat housing to check on the condition of the old thermo. Turns out that the previous owner drilled a few holes on the plate of the thermostat basically rendering it useless. Coolant flow went thru it regardless of coolant temp. I replaced the thermo, o-ring, and gasket with VW part# suggested by the guys here, and I picked the one that opened at a lower temp. 2) Pulled the radiator out and had it recored. The cost was $600 and the old radiator was recored to a 4-row, staggered tube core. The original was a 3-row, in-line tube core. The radiator shop noticed come calcium buildup in 1/3 of the old radiator, which needed to be rodded out (at the minimum). I believe rodding out would have been sufficient but the price difference was minimal and I liked the idea of a brand new staggered-tube core. Turned out to be a good decision. 3) My fans were fine but the spade connectors did need some cleaning. Electrical contact cleaner took care of that fine. One of the fans was spinning the wrong way (which definitely was a suspect to my overheating prob) and that only needed wire switching to spin the fan the correct way. Both fans now "pull" air thru. Unlike the 308, my 326 cooling fans are behind the radiator thus "pulling" is the proper flow direction. 4) I went ahead and replaced the cooling fan switch with the VW Part# recommended by folks at this site. It kicks in at a lower temp than the original. 5) Since the project required removal of the bottom fiberglass covers I went ahead and re-fiberglassed the scraped areas and even had time to put some aluminum plate shielding for future scrape protection (while the radiator was recored for 2 days). 6) Blew out the heater core hoses connected to "t"s in the bonnet area. 7) Installed a coolant drain "T" valve recommended by some really smart guys on this site. 8) Bled the coolant several times after reassembly and made sure coolant entered the heater cores. 9) Drove it like it was stolen. The coolant temp stays at 175F constantly. It will go up to about 180F on a really hot day and hard run but once the fans kick in, the temp will drop immediately to 175F. Some might even say it runs too cool. I've been running in on really hot hill climbs and she stays very cool. I found the project to be quite easy. Certainly much easier than replacing the fuel lines. Certainly a DIYer. A car lift would have made the job much, much easier. I hope this helps some of you out there who are having temp probs with your 328. I spent a total of $700 counting the recore job. Took me a week to finish it. Pretty satisfying though.
