I have a Mk1 55 S. 3 weeks ago I was going on highway and it overheated blowing the head gasket. Got a mechanic to fix it, including a new thermostat and fan switch. Bit the reason why it overheated is still there. While driving in the city, temperature stays around 90 degrees, but when going on highway at 120 km/h temperature starts to go to 100 degrees. If I reduce RPMs it will eventually drop down to 90 degrees. What could be the problem?
Technical Overheating at high speeds
- Thread starter dj_jl
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Technical Overheating at high speeds
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enoguth collant in your system , may have an air lock so youll need to bleed your system, enough oil? radiator blocked with crap? these are just suggestions, have a look round the enigne
Right after head gasket repair I checked oil and it was very low. I changed oil filter and added a lots of fresh oil and oil level is fine now.
One of my first thoughts was airlocks, I've been doing proper bleeding, but it still doesn't help.
Now that you say about crap in radiator, I opened bottle where you top up coolant and
saw a lots of brown stuff on the walls of it. Will try to clean it.
I also noticed that there's a small oil leek from between engine head and block with coils. It doesn't seam to leak a lots as I haven't noticed any drop in oil level.
One of my first thoughts was airlocks, I've been doing proper bleeding, but it still doesn't help.
Now that you say about crap in radiator, I opened bottle where you top up coolant and
saw a lots of brown stuff on the walls of it. Will try to clean it.I also noticed that there's a small oil leek from between engine head and block with coils. It doesn't seam to leak a lots as I haven't noticed any drop in oil level.
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in your radiator your lines maybe blocked a bit and coated in that brown much you was on a bout, i think that must of been from your head gasket failure. erm not really sure how to clean inside it. What i would do is take ur radiator off and flush it through with some cleaning stuff liek ya put down ya plugs in ya sinks at home. If this forum wasnt around and i never asked anyone thats what i would of done
Well, I drained the cooling system, a lots of brown stuff came out. I then took out the radiator and ran water through it and a lots of rust came out. After some good rinsing I think I managed to get most of the stuff out. Also the front part of the radiator had bugs and small rocks stuck between the plates. I cleaned it as much as I can. In one spot it has hit something bigger and the tiny plates have melted a bit, but I hope it won't cause any problem. I assume there's more of the rust inside the cooling system. Since thermostat looks like is sealed with silicon sealant that I don't have, and since I need car tomorrow I didn't take it off. The best I could do is put it together, fill it up with water, run it, so that water pump runs it around the engine, and then drain it. After some times it started to get cleaner (it got too dark to continue). Probably will have to continue it another day.
OK, a few days back I was doing some more flushing with water and got most of the crap out. Yesterday I got a bottle of Wynn's Radiator Flush and used it. After that used deionized water to clean it and finally put in some fresh coolant. This evening I'll have a journey on the highway to the neighboring city, that should make it a good test drive. Hopefully it won't be heating up anymore.
Had a ride on the highway with 4 people in the car one way, 3 when coming back. And the tendency to heat up was still there.:bang: It was more obvious while driving in 5th gear, switching down to 4th seamed to improve situation a bit.
So I'm starting to suspect water pump to be the reason. It feels like it's worn and doesn't circulate water good enough for a highway drive. Does this sound reasonable? Also on higher revs there's a clicking noise coming from the engine, could it be coming from the water pump?
:bang: It was more obvious while driving in 5th gear, switching down to 4th seamed to improve situation a bit.So I'm starting to suspect water pump to be the reason. It feels like it's worn and doesn't circulate water good enough for a highway drive. Does this sound reasonable? Also on higher revs there's a clicking noise coming from the engine, could it be coming from the water pump?
Replace the water pump & fit a new rad (they arent as expensive as they once where).
The rad should have been replaced or at least taken out and flushed if the head had gone.
Make sure also its the correct anti freeze mix, as this will also cause problems in its self.
Martin
The rad should have been replaced or at least taken out and flushed if the head had gone.
Make sure also its the correct anti freeze mix, as this will also cause problems in its self.
Martin
Uno driver
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I have same problems, but I think the reason is hot weather. Yesterday at night, when it was cold (16 degrees) I was driving 150km/h for 50km and temperature was normal, but when it's hot (~35 degrees) and I'm driving 120-130km/h temperature is around 100 degrees.
In theiory the outside ambient air temp shouldn't make much of a difference to temp when driving at speed.
I think it is probably the water pump, or even the thermostat not opening fully.
Jon.
I think it is probably the water pump, or even the thermostat not opening fully.
Jon.
I also don't think it's ambient temperature. The last drive I wrote about we left after 10 PM and came back after midnight, so it wasn't during the hot hours. And last summer I've been driving in hot days and didn't have this problem.
I doubt it's thermostat because it has been changed as part of head gasket repair.
I doubt it's thermostat because it has been changed as part of head gasket repair.
OK, so got new water pump, timing belt and tensioner, changed them, everything seemed to be fine. Decided to go on a test drive on highway and it was basically like before, when I went up the hill, temperature raised to 95, but then dropped back. When I was almost home temperature raised to 100 degrees and didn't drop. I stopped sensing that somethings not right. Checked engine and found out that it's very low on coolant. Added some water, bleeded system and managed to get home. Checked coolant and it was low again.:bang: Filled it up again. When starting the engine, it was missfiring but after giving some gas it started to run fine. Collant was leaking from the fill-up bottle cap, checked exaust and saw steam coming from it.:bang: So it looks like my head gasked is gone again.:bang:
Decided to go on a test drive on highway and it was basically like before, when I went up the hill, temperature raised to 95, but then dropped back. When I was almost home temperature raised to 100 degrees and didn't drop. I stopped sensing that somethings not right. Checked engine and found out that it's very low on coolant. Added some water, bleeded system and managed to get home. Checked coolant and it was low again.:bang: Filled it up again. When starting the engine, it was missfiring but after giving some gas it started to run fine. Collant was leaking from the fill-up bottle cap, checked exaust and saw steam coming from it.:bang: So it looks like my head gasked is gone again.:bang:
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Hmmm
If the headgasket signs are still there
The question is - ur head block stuffed? and was it shaved (or what ever the fancy word for it is) when the new headgasket was put on?
Ziggy
If the headgasket signs are still there
The question is - ur head block stuffed? and was it shaved (or what ever the fancy word for it is) when the new headgasket was put on?
Ziggy
That's bad luck dude... It sounds like you know what you're doing in there.
Essentially the system sounds as good as it can be (bled, flushed, new coolant, new pump) but the gasket definitely sounds like it's gone (again?).
Once you bled a system, if it's still getting air in it, then that's usually a sign of a shot gasket. It's the air (gas) in the system that blows the coolant out of the reservoir and stops it circulating through the radiator (causing overheating).
So, I'd take the head off and have a look. If the crew who fixed it didn't flush the radiator out then I'm worried about the "quality" of the repair too. Did they even replace the gasket? It's almost impossible to wreck a new gasket so soon!
Ralf S.
Essentially the system sounds as good as it can be (bled, flushed, new coolant, new pump) but the gasket definitely sounds like it's gone (again?).
Once you bled a system, if it's still getting air in it, then that's usually a sign of a shot gasket. It's the air (gas) in the system that blows the coolant out of the reservoir and stops it circulating through the radiator (causing overheating).
So, I'd take the head off and have a look. If the crew who fixed it didn't flush the radiator out then I'm worried about the "quality" of the repair too. Did they even replace the gasket? It's almost impossible to wreck a new gasket so soon!
Ralf S.
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I doubt they flushed radiator. They even fitted coil pack back using the old o-ring where part has fallen off causing an oil leak:doh:. He showed me the old gasket pointing where the problem was, so I assume that it really was changed .
I have arranged with a mechanic (a different one obviously) to pick it up tomorrow. Let's hope he will fix it properly.
.I have arranged with a mechanic (a different one obviously) to pick it up tomorrow. Let's hope he will fix it properly.
Cracked head. Maybe only hairline cracks but opening up with temperature rise :idea: Good luck with it m8
A little update. Head gasket has been repaired more than a week ago. Took it on a test drive to the mountains and overheating problem is still there. What I noticed is that each time when we stopped to let engine cool down radiator fan was on for a very long time (a few minutes). So I stared to suspect a blocked radiator problem. It seams it's blocked so badly that flushing doesn't help.
Today I stopped at some random garage and mechanic took a look. I explained him the problem, he reved up engine for a few minutes, checked radiator and hoses and noticed that fan is on for a long time. So he told me that radiator is partially blocked and must be changed.
Let's hope a new radiator will fix the problem. If not - cracked head?
Today I stopped at some random garage and mechanic took a look. I explained him the problem, he reved up engine for a few minutes, checked radiator and hoses and noticed that fan is on for a long time. So he told me that radiator is partially blocked and must be changed.
Let's hope a new radiator will fix the problem. If not - cracked head
?