help tu 1.4

[dazza1223]

hi all i was wishing for some help i have a 306 tu engine 1.4 it had a leek in the rad on the m40 i got it home ok it over heated so i stop the car and fill it up again so i put a new  radiator in it ever since  the it all way over heat so i look it some where and thay checked it and thay said yep it the head gasket so i got all the pats new head gasket set new water pump and timing belt and new thermostat new antifreeze got the head skim put it all back toghter on it doing the same thing as before just over heating more on going up hill so i re bleed it with the coke bottle trick but the same so i took the thermostat out and it run fine not i dont get any hot air in the cap when on a long run ony get hot air when it ticking over so i put a nother thermostat in thinking it will be ok now but it still the same ive had  ppl looking at it thay dont know what it cued be so plz can some one help

[Nexus]

Just a question, do you currently have a leak with the coolant system or has that now been resolved?

If you replaced the radiator with a (brand) new one and correctly bled the system there technically should not be an issue. You should have pressure in the coolant system, hot air through the cabin begins at around 65 degrees on the gauge and your engine shouldn't really be any hotter than 90 degrees when fully warmed up and ticking over.

Your top hose should be very hot when the thermostat opens however if there is an airlock in the engine block behind the thermostat, the thermostat will not open, resulting in an improper bleed. The sensor is essentially reading the temperature of the airlock, not the water. Obviously not to be patronizing but it took me a few goes to find the optimum way of bleeding the system in the right order and timing.

I would strongly recommend changing your coolant temperature gauge on the engine block and ensuring a good bleed. I generally see this as an item that should be replaced every so often anyway (You will need to re-bleed). A gauge is only an indication of what the coolant temperature is when it is cycling around the system and a sensor is prone to losing its accuracy with wear. Is the car actually hot or is it just a dodgy reading etc. When you describe the car as overheating, when does this occur? Does it rapidly fluctuate up and down during driving or just get hotter and hotter during warm up and never stabilizes?

[dazza1223]

hey thank u for getting back to me!! nope no leek any more the car not losing water all any think and i can Chance that sensor but what i did was i drill a itty hoe in the top off the thermostat so let air bypass but with the thermostat in and the car sit ticking over it but but no heat but the fan kick in and then i fill the pipes and thay are hot but the one what to to the heating in the cap one is hot and the over one is warm??? and if i drive it for about 30min it will over heat and the stop light will come on and i stop and bleed the thermostat housing there load off air coming out off there so i think o it be OK now but i drive a bite more and bleed it again and it loads more it but dont stop sucking in air but if i take the thermostat out and drive it fine it dont over heat the heater in the cap will get hot only when the car ticking over but soon as i drive it it goes cold again but when drive the car up hill with out the thermostat it don over heat it all fine it dont play up

ps u said u hade to do it in the right order and timing can u give e them step so i will see if that help? thank

[Mighty306]

Have you got yourself a Haynes Manual for the 306?  If not get yourself one.  (Second hand they're only about a fiver on eBay).

Follow the steps in 1A.18 to properly bleed the system.  If it still overheats then something 'ain't right.  Did you do the HG yourself?

[dazza1223]

yh i look in there and it did it that way and no a car mechanic did it but he move a way now and i can get hold off him

[Rippthrough]

Have you bleed the air out of the top of the thermostat housing AND the heater hoses?

[dazza1223]

yh i did all that and with the thermostat in i drive it it over heats then i bleed it again and again it just keep sucking in air all the time but if i take out the thermostat it no air

[Nexus]

I would very much recommend not to drive the car until you find out what is causing the car to reach a temperature serious enough to cause a Stop light illumination. Continued use at those temperatures will cause major damage to engine components.

You mentioned that you have drilled a hole in the thermostat, this shouldn't need to be done as the complete thermostat and housing can be bought from ECP for about £7 and there is a bleed screw on the engine block where the thermostat is located (1 of 3 that you need to do). It is very important that this part of the system is bled correctly, if there is an airlock in this area your temp sensor will read incorrectly and the thermostat wont open thus no coolant flowing to radiator. Hense why it works fine when the thermostat is removed.

   


If you are absolutely sure that you have bled the system correctly and thoroughly (according to the Haynes manual) but continue having problems I personally would be investigating the radiator cap, verifying the HG was skimmed and installed correctly and considering a coolant system pressure test. It can take up to three engine warm-ups (90 degrees) and cools downs to get a decent indication that all air is out and coolant level correct.

[dazza1223]

it cam to mind to me to day so i did fit a new radiator cap but lol still the same but as i cant under stand why in geting so much air in it wood it do this this the head is cracked? ps and yh the head was skimmed and how did u bleed ur one with a coke botil?

[Nexus]

For me personally, I use a Lisle Spill-Free Funnel as a header tank when doing coolant.

   

[dazza1223]

hi yh ive uesed a 2 litre coke bottle cut the top off i was just thinking wood it be a cracked head?

[Nexus]

It is not good to jump to conclusions - Start with the simple things first and work your way up in severity.

If I was having this problem myself I would be checking:

• Bleeding procedure
  
• Condition of spark plugs in each chamber
  
• White smoke while engine is warm/hot
  
• Endoscope (camera) down in to the combustion chambers
  
• Perform a coolant system pressure test (a garage can also do this for you)
  

All of the above are checks to check HG. The big question is are you actually losing coolant? Coolant will either be lost with a pipe or rad leak, or through the head gasket. If you are NOT losing any coolant, then surely it can only be an airlock causing the issue. If you mentioned that the system works fine when the thermostat is removed, but overheats when the thermostat is IN, then it is an airlock which will be down the how the system is being bled to begin with.

Without seeing the vehicle and how it behaves in person it is difficult to pinpoint anything absolute. What I have learnt is not to overthink things and to start with small obvious things which may have been overlooked. Small details can cause havoc if not followed correctly.

Hope this helps

[dazza1223]

may be i will start all over again doing all the check u said and if that falls i will get a coolant system pressure test dne on it ive done load off cars and ive never never seen somthink like this be for..... so i will drain it all and have a go again what the fist bledder do u start with?

[Mighty306]

Open bleed on thermostat housing and where heater hoses enter bulkhead.  Also open bleed in top of rad if you have one.  Close each as coolant starts to p*ss out.  The highest is the heater hose bleed and so will be the last you should close.

Haynes then recommend you run the vehicle until hot with the header funnel still fixed in place, and leave it in place until the car has cooled again.

When warming the car up turn the interior heater to full and make sure the air coming through is properly warm.  That way you know that part of the system has filled properly.

Suggest you try all this with a thermostat fitted in the cooling system.

[dazza1223]

ok i will report bk when i do it and thank guys for all the help!

[dazza1223]

o i was out there last night and i drain it all out then i put a 2lit botil as a header and fill it up

then i Open bleed on rad that air cam out then water the i closed it

then i open Open bleed on thermostat housing and load more air cam out then water then closed that

then the heater pip bleed that i have to rev the car to get all the air out

then i got in the cab then the hearter was warm note hot and the temp was 90c

so i took it for a drive along the sea front then i saw the temp going up to 97 98 99 then i shut it off then i Open bleed on thermostat housing and there was just hessing nose and afer 5 min water cam out
then i drove it home and again 98 Open bleed on thermostat housing and a loads my air come out

[Rippthrough]

You shouldn't need to rev the engine at all to bleed the top heaters, your bottle is not filled up enough if that's the case, you'll just push the air around the engine.
Also, you need to leave it idling to get up to 90c or so so the thermostat opens and rebleed.

[dazza1223]

yh that with a 2 litre coke as a header tank but ive done it a gain but it still over heats where am i going rong? lol

ps i read all over the net and im seeing load and load are have the same thing as me but thay haven't resolve it yet?

[Mighty306]

As Rippthrough says it sounds a little like you're not getting the level in your coke bottle high enough. Is there a good seal between the coke bottle neck & rad? I make a ring of rubber cut from a bike inner tube to seal it.

It's also worth checking you haven't got damp in the foot wells. If you have it's poss originating from behind the centre console.  It's quite common (from what I've read) for an HG failure to damage the heater matrix. If you are losing coolant but it's not obvious from where that's a candidate.

[dazza1223]

yh i just did it a again with out reving  and water was coming out fine it mate and and the coke botl got a good seal and not im note loseing any water and no the foot wells it all dry

[dazza1223]

sorry for banging guys!

i was doing some more digging about and i saw on there over some forums and i come across this he is have the same thing as im haveing

Hi!
This is my car: 1999 Peugeot 306 1.6 manual. (With AC)

This is the problem:
I could really need some inputs, since i am stuck...

The problem:
-The temperature gets to hot. 100-110c
-Driving up a hill makes the temp rise and goes slightly into the red.
-Unplugging the fan coolant sensor so both fans operate at full speed does not help
-If i open the bleeding screw on the hose to the bulk head i get a steady stream of water that follows the revs. (Rules out waterpump???)
-I get a steady flow of hot air from the heater.
-I do not lose any coolant

The low speed fan that should kick in at 97c does not kick in before temp gauge shows appr. 105-107c
High speed fan should kick in at 107,c but it does not engage. If i undo the sensor and put my heat gun right at it, it will make the high speed fan go.

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What i have done:

-Changed thermostat=no difference
-Changed radiator + coolant= no difference
-Changed temp sender to gauge and temp sender to fan ECU= no diffence
-New earth cable from gearbox and battery= no difference
-Cleaned cable connection the the fans=no difference
-Tryed another (used) fan controll unit ECU (Bitron) = no difference

I im stuck with this problem, so if anyone have any ideas on what could be wrong let me know :-)

and then he fixed it but

I let the flushing product in for 6 days. Then i drained the system. I could find some particles in the water.


Then i flushed the system again just with the garden hose, then topped it up with just water and bleed the system.
Then everything seemed to be in order! The temperature was stabile 85-90 no matter if it was a hill or the motorway. So i was very satisfied.
I drove with just water in the system for two weeks with nice stable temperatures.
Since everything seemed to work, i decided to add coolant today. So i drained the system again and topped it up with 50/50 water/coolant and bleed the system.


But then suddenly i was back where i started!!!!


When driving uphill or pushing the engine (motorway) the temperature rises to 95-100. The same problems i had before, just not so high temperatures (100-110)
Standing still idling the temperature is just under 90.



Now i am just frustrated and fed up!!


Any ideas? Why is it happy with just water, but when i use water/coolant i have problems?

im in the same boat as him

[Rippthrough]

Well, the fact his sensor works out of the car but not in it and that he got it running right until he changed the coolant again leads to the same conclusion - both of you still have air in the system somewhere.

If you ask in general there might be someone local who will take a look at it for you, you're too far away for me.

[dazza1223]

i have two ppl looking at it and thay said well it must be a cracked head lol but im note sure it is?

[dazza1223]

hey all just a up date on this junk!! i was out there from 6pm to 8 , yh i fill it up and i got car fast idle 3000 rpm with the coke bottle fill up and i was watching it and bleeding it but no air and there was no bubble coming up in the the bottle and the fan was kicking in and out it was not getting past 90 at fast idle so i gave it a good run on the a23 for 40min and the temp was getting up in to the red when i was doing 70 and if i kick it to 80 then it will go pretty much in the red

[Rippthrough]

If you're certain after that it was bled then I'm guessing the head gasket wasn't done properly - have you checked the compression?

[dazza1223]

no i ant done that yet but as i said when thay check it thay said all the water is going around the moter fine and thay was using a laster temp and it was all ok with the temp