307 Petrol losing coolant

L

luthier

Well-known member
1000+ Posts
Fellow Frogger
Joined
Oct 31, 2004
Messages
1,268
Location
Northern NSW
One of my boys has a tidy looking 307Petrol Hatch 1.6 2003 model. It has about 300,000K's on the clock.
It recently had a new clutch but now he says though he can't see anything dripping that the coolant needs increasing amounts of topping up.
Instantly I suspect the head gasket as you do.
I'm thinking an engine graft would be preferable to doing the headgasket depending on cost and availability.
It is too good in the rest of it to trash, aircon works great and with good running gear it runs nicely and handles well.
Any thoughts either way? If engine graft does anyone know of a good engine going for a fair price?
 
Heater core orings


Garage C5 X7 3008 XTE
Gone but not forgotten 206 GTI 180 306 XR SED 405 MI16 x2 xzara VTS 406 SV 206 XT Berlingo 2011 (best car ever) 306 HDI 307 XSE HDI touring
Fix it right the first time
 
Wow thanks David, I hope you're right. His heater doesn't work so I'll make sure it's properly blocked off.

Nope, just asked him and the heater is totally bypassed.
I'm going to get him to fill it to max, then bring it to operating temp, then go and sit it on the new slab and see if there's any leaks for half an hour.
We'll proceed from there.
 
Last edited:
Also make sure no leaks go onto the exhaust manifold and evaporate. I'm not sure if there is any pipework there, but this is sometimes an issue with coolant loss but no obvious leaks.
 
So many Kms, Time for the Town Mechanic, slightly up from Bush Mechanic

CHEMIWELD, may last 6-12 months but cheap
 
Maybe water pump. How quickly is it losing coolant?

300,000 Kms. When was the timing belt last replaced along with the water pump?

Might be due for a second belt etc.

Cheers
Roland
 
Update on the 307 problem child. After giving it the chemiweld it has not really recovered. It overheated badly as soon as the chemiweld went in and by a masterful series of coasting with the engine turned off and then switching back on I got home in it without spending any time up in the overheated zone.
So it was either a water pump or headgasket or both.
I found no blades left on the impeller so I assumed that a new water pump and of course timing belt was a good possibility of being the problem.
However now with all that installed it still runs too hot.
Runs on 90 then when stressed up a steep hill gets up over 100. Doesn't actually go right into the red now so maybe the headgasket isn't at fault. I trashed the inside of the thermostat when it was first misbehaving but that should make it run cooler if anything.. But there's still a big problem that seemed to first occur right when it gargled chemiweld.
I suspect that the old bits of the impeller have got stuck in small waterways through the head and then the chemiweld cemented them in there permanently and blocked up flow in some of those places.
However I haven't got time to investigate so unless any of you genii have some other theory I'm going to go down the track to get a replacement motor. It seems there are quite a few available round Brisbane for the magic price of $599. I consider this to be preferable to trying to find the mystery problem along with a headgasket and probably having the head worked on and all that garbomumbo.

God these kids are expensive.
At least we can transfer the new timing belt kit, aux belt and very recent clutch and his aircon works well, but it's borderline whether it's worth reviving because the hood lining is stuffed, the indicator stalk is too, fuel gauge not working, nor is the horn, and the window switches on the drivers door just hang from wires with LED buttons but no covers. Lots of little things that add up to annoy the $hit out of me.
So it really is a mountain of munt except that it's straight, handles and stops fairly well and the seats are good. So with a low K's motor with a year's warranty it might become viable again.
 
Find a 307 at a wreaker and get a deal on the the parts you need.
A new hood lining can be done for approx $200-$280 in Brisvegas.

Just makes sure same VIN series.
Horn not working will be either horns behind bumper or someone has already opened the steering wheel broken the wires while trying to replace the Comm unit which controls the stalks.

Add it all up and see if worthwhile to you to keep driving.😣

Sent from my SM-G900I using aussiefrogs mobile app
 
I'd put a brand new thermostat in there first and then see if it stays on temperature.

Have you checked the radiator?
It might be worth adding some radiator flush to give everything a good clean out (including left over chemi-weld).

If nothing works, then make a decision to get all parts needed to repair vehicle and/or look to a replacement engine/vehicle.

Cheers
Roland

:banana:
 
Also make sure the cooling fan is working at both high AND low speed.
If the low speed resister is blown, the fan will not come on until the engine is over 100c.
Probably not the only problem, but it may be contributing to it.
 
gromzx said:
Also make sure the cooling fan is working at both high AND low speed.
If the low speed resister is blown, the fan will not come on until the engine is over 100c.
Probably not the only problem, but it may be contributing to it.
Click to expand...

I think this may be the case. Just waiting for the thermostat then I'll give it the test.
Where can I find that resistor? Is that down front in the grille? I was expecting it would be a sensor in the thermostat housing like the 406.
I'm also going to do a reverse radiator flush and attempt to find /blow out bits that might be blocking the radiator at the bottom.
There is also the 'sniffer' test to find if any gases from combustion are getting into the water system to determine whether the head gasket is actually blown.
If that proves negative I'm considering looking at a replacement radiator.
No point in replacing the engine if it isn't the problem right?
 
Just made a weird discovery.
After flushing with radiator clean I still don't have the right thermostat but it should actually run cooler without it.
Anyway I removed the temp sensor on the head.
This runs in the water jacket right? So I was very cautious getting it out as the thing was still quite warm.
But no water came out.
I took it right out, filled the recovery bottle up full, started the engine but nothing comes out that hole. I've bled the little bleeder on the thermostat housing.
Thus we have a blockage and a damn perfect seal on it as well. Looks like chemiweld did a great job in precisely the wrong spot.
Can anyone think of a solution apart from total dismantling/engine swap scenario? Would there be any access if I removed the thermo housing to maybe poke a wire in?
I'll start by poking a wire in the sensor hole.
I fear it's seriously chemiwelded up.
Let this be a salutory lesson, learned again, never to use chemiweld unless the actual problem has been properly diagnosed. Thus a 'chemical sniffer of the water test' could have first ascertained that there was no head gasket leak so the water pump would then have been found and the problem would have been solved.
But now I probably have to take off the head as there's only time lost there, of which I did not want to part with, so if it's possible to find and chip out the blockage then perhaps it's only a head gasket replacement which is relatively cheap.
 
Last edited:
This is the reason if we must use stop leak we use the nulon one, because it's a liquid. None of those rocks that block up everything!

Sent from my SM-G930F using aussiefrogs mobile app
 
luthier said:
...Where can I find that resistor? Is that down front in the grille? I was expecting it would be a sensor in the thermostat housing like the 406...
Click to expand...

Normally at the bottom of the fan shroud, under the fan, or in that general area.
 
The temp sensor on the head doesn't run in water, it just measures the temp of the metal. So forget what I said about the chemiweld blockage.
The sensor on the thermo housing operates the fan through the ecu.
When disconnected the fan should run on low and when ignition is turned on it should go to high speed. Neither of these are happening so next to inspect the relays.
Things may not be so drastic.
 
Relays and relay connections rarely seem to be a problem in Oz, only in UK and EU.
I wouldn't mind guessing either thermostat or thermo switch (most common) but that would only cause it to run hot, not lose coolant necessarily.

Learn from my experience, if replacing the thermo switch, buy OEM from Peugeot; not a cheapy from eBay or other online sources.
 
I've checked the relays and they seem good. The fan comes on full at about 95. Going up a long steep hill it gets up a bit over 100 but comes back down again when stress is relieved.
I reckon the water loss was the recovery bottle cap which has a slightly dodgy thread but can be well tightened as long as you persist.
So though it's slightly higher than I like it isn't overheating and is usable. It still has a hollow thermostat and still is only running straight water so I reckon once the thermostat arrives and coolant is installed the job's right or he'll be looking for a replacement thermoswitch that might activate the high speed fan a bit earlier. I can imagine coolant making it run slightly cooler and perhaps when the proper water flow is returned with the thermostat the thermo switch will behave a little differently. It would then be getting hotter a bit earlier in the thermo housing which would cut the fan in a bit earlier I think.
 
Just following up on your comment there. The dodgy thread on the overflow bottle. On my 206 the cap pressurizes the system does it not? (I assume on your 207 also). Could that be the cause of the coolant loss as you say; AND temp issues?

Would it be worth throwing on another reservoir bottle and/or cap from a wreckers at some stage?
 
You must log in or register to reply here.
Top