Here is my reason for the decision above. My car consumes nearly 5-10 liters of fuel within the time it takes my engine to warm up ie when the temperature gauge moves from zero to the middle of the calibration. Once the temperature gauge gets to the middle (takes about 20-30 minutes to achieve), my fuel gauge stabilizes and starts functioning like it should (drops normally like a four plug engine should). I scanned the car but no fault was detected as responsible for such abnormal fuel consumption before the engine warms up. I, therefore, want to fix a new thermostat. Car specialists in the house, kindly let me know if it’s a wise decision; are there other areas i may be neglecting; what do i look out for etc. Thanks in advance.

Any advice? I want to get the job done as soon as possible.

What makes you think your car's thermostat is the culprit for the high fuel consumption, if at all the car still have engine thermostat? How are you even sure that your car consumes excess fuel? Because of the way the fuel guage is acting when engine is cold? Have you considered that it could be an instrument cluster problem, making the fuel guage to drop as temp guage rises? If really, your car is consuming upto that amount of fuel that you said, then it should be giving other symptoms like emitting black smoke from the exhaust tail. Is yours doing that? Does the electric radiator cooling fans still work according to factory connection.ie. only switch on when temp guage reaches the middle of the guage? Do they spin as soon as you switch on the ignition & remain constantly on as long as ignition switch is on? Have you checked to know if the thermostat is still there? Answering all the questions above would help me know if the problem is the thermostat or something else.

A stuck open thermostat would make a car run rich & would delay the electric radiator cooling fan from switching on. But there are ways of checking if the thermostat is still good. Remove the thermostat from the car, boil water in a pot & drop the thermostat into the boiling water. If the t-stat is still good, within seconds of dropping it in, it will open before your very eyes. And to know if it still closes, shut off the fire boiling the water, while the t-stat is still in & allow it to gradually cool. As the water temperature drops, you will see the t-stat gradually closing. That will confirm that the t-stat is still ok. Or you can put the t-stat in cold water in pot & place on it your cooking gas or stove & ignite the gas cooker nozzles. As the water gradually warms, the t-stat will gradually start opening till it opens completely when the water must have started boiling. If you have a thermometer, it would help to know at which temp that the t-stat opens & closes. It will tell you if the t-stat still opens at factory temperature. The factory temp would be engraved on the t-stat. It always pay to conduct this test on t-stat before you replace it, so that it wont be a waste of money replacing what is not faulty.

I dont know how good your CTS (Coolant Temperature Sensor) is. Because faulty cts would make your car run very rich or thirsty when a car engine is cold & hot. Most times, when it fails, it will be signaling "engine cold" to the ECU all the time, making the ECU to make the injectors to spray in excess fuel, thinking that engine is cold all the time, based on info it receives from the CTS.

Ikenna.

I honestly don't know if the thermostat is the culprit. The engine does not emit black smoke, my mechanic even gave the engine a clean bill of health. When i bought the car, the thermostat was not there, and the electric radiator cooling fan spins as soon as i turn on the ignition and continues till i turn it off.

I will check the CTS and find out if its still functioning. Thank you Ikenna.

There is your problem; no thermostat. Dont bother looking elsewhere. Even if the CTS is faulty, the absence of thermostat contributes to the high fuel consumption, because it means that the engine will be running cold for a very long time before it warms, and the cts would always signal to ecu what its sensing: engine cold, making the ecu to always make the injectors spray in excess fuel since its been told by the cts that engine is always cold. So you see that its not cts fault, but the absence of thermostat, worsen by constant spinning of radiator cooling fan, by preventing the fluid in the cooling system to warm. Even if you cant re-connect fans back to factory (to spin only when temp tries to exceed normal engine operating temp.ie.exceed midlle of temp guage), get the correct good thermostat of that your engine & fix it back. Not just for the fuel economy, but for the durability of the engine's sake which is already suffering, with the absence of thermostat & constant spinning of the radiator cooling fans.

Ikenna.

Thank you Ikenna. One more thing. Is it possible to get the fans working according to factory setting without a thermostat?

Cruise-z:
Thank you Ikenna. One more thing. Is it possible to get the fans working according to factory setting without a thermostat?

Yes, its possible. You just need to find the original connection.

Ikenna.

Pending when i buy a good thermostat, do you advice i fix the fans first or both together?

Ikenna351: What makes you think your car's thermostat is the culprit for the high fuel consumption, if at all the car still have engine thermostat? How are you even sure that your car consumes excess fuel? Because of the way the fuel guage is acting when engine is cold? Have you considered that it could be an instrument cluster problem, making the fuel guage to drop as temp guage rises? If really, your car is consuming upto that amount of fuel that you said, then it should be giving other symptoms like emitting black smoke from the exhaust tail. Is yours doing that? Does the electric radiator cooling fans still work according to factory connection.ie. only switch on when temp guage reaches the middle of the guage? Do they spin as soon as you switch on the ignition & remain constantly on as long as ignition switch is on? Have you checked to know if the thermostat is still there? Answering all the questions above would help me know if the problem is the thermostat or something else.

A stuck open thermostat would make a car run rich & would delay the electric radiator cooling fan from switching on. But there are ways of checking if the thermostat is still good. Remove the thermostat from the car, boil water in a pot & drop the thermostat into the boiling water. If the t-stat is still good, within seconds of dropping it in, it will open before your very eyes. And to know if it still closes, shut off the fire boiling the water, while the t-stat is still in & allow it to gradually cool. As the water temperature drops, you will see the t-stat gradually closing. That will confirm that the t-stat is still ok. Or you can put the t-stat in cold water in pot & place on it your cooking gas or stove & ignite the gas cooker nozzles. As the water gradually warms, the t-stat will gradually start opening till it opens completely when the water must have started boiling. If you have a thermometer, it would help to know at which temp that the t-stat opens & closes. It will tell you if the t-stat still opens at factory temperature. The factory temp would be engraved on the t-stat. It always pay to conduct this test on t-stat before you replace it, so that it wont be a waste of money replacing what is not faulty.

I dont know how good your CTS (Coolant Temperature Sensor) is. Because faulty cts would make your car run very rich or thirsty when a car engine is cold & hot. Most times, when it fails, it will be signaling "engine cold" to the ECU all the time, making the ECU to make the injectors to spray in excess fuel, thinking that engine is cold all the time, based on info it receives from the CTS.

Ikenna.

Ikenna you are too much, Thumbs up

nice answer by ikenna...but i think he shud fix the thermostat n fan together..cos if he connects the fan to the default connection...ie to switch on when the engine is hot..since there is no thermostat in the car..how would the cars onboard computer know that the engine is hot?

cretin: nice answer by ikenna...but i think he shud fix the thermostat n fan together..cos if he connects the fan to the default connection...ie to switch on when the engine is hot..since there is no thermostat in the car..how would the cars onboard computer know that the engine is hot?

Via CTS.

Ikenna.

Oga Ikenna I'm having a new issue with my 307 o!
I complained earlier that a rewire connected my fan directly to my alternator without my knowledge to keep the fan on whenever the engine is on.
I reversed the connection 2 weeks back and the temparature guage is now always roughly at the middle as you said, but I just noticed for the last few days that even though the fan turns once in a while when it should, on especially hot days or when I'm in traffic, at times the fluid in the radiator tank just starts boiling and pours out.
This never happened in over 4 years of using the car, what could be wrong?

bigx: Oga Ikenna I'm having a new issue with my 307 o!
I complained earlier that a rewire connected my fan directly to my alternator without my knowledge to keep the fan on whenever the engine is on.
I reversed the connection 2 weeks back and the temparature guage is now always roughly at the middle as you said, but I just noticed for the last few days that even though the fan turns once in a while when it should, on especially hot days or when I'm in traffic, at times the fluid in the radiator tank just starts boiling and pours out.
This never happened in over 4 years of using the car, what could be wrong?

A lot coud have caused it.

If air is trapped in a cooling system (airlock), it would always overheat the engine when the fluid in the cooling system warms (airpocket). This usually happens when coolant is drained & refilled without properlly bleeding the system.

If the cooling system thermostat is removed or stuck open, the engine would overheat as soon as it warms & stays long in traffic jam.

If the radiator cap or the expansion coolanat bottle/container cap is not well closed or tight, the coolant will over boil. Likewise if there is leak on any of the cooling system hose or the radiator, the same will happen.

Most Peugeots I know do have bleed screws for bleeding the cooling system. Those that dont have the bleed screws are designed in such away that as you are re-filling the system after flushing, air will be going out of the system as well, and there wont be need for bleeding the system.

Ikenna.

@bigx

I forgot to ask. How fast is the spinning of the fan since you reconnected the fan to factory? Is the speed the same with when it was running constantly?

Why am asking is because if the fan is not fast enough, it wont push or suck heat out of the radiator. Hope no one has tampered with the fan relay.

Ikenna.

Ikenna, i am so grateful for the insightful responses. I will need a specialist to handle the job for me cos i want it done right. If anybody knows where i can visit in Lagos to reconnect my radiator fan to factory setting, fix a new thermostat, check cts, airlock etc kindly let me know. Thank you in advance.

he cud also flush and steam wash the radiator in n out..and dirt clogs up n reduces the cooling surface area of the radiator

Ikenna351:

A lot coud have caused it.

If air is trapped in a cooling system (airlock), it would always overheat the engine when the fluid in the cooling system warms (airpocket). This usually happens when coolant is drained & refilled without properlly bleeding the system.

If the cooling system thermostat is removed or stuck open, the engine would overheat as soon as it warms & stays long in traffic jam.

If the radiator cap or the expansion coolanat bottle/container cap is not well closed or tight, the coolant will over boil. Likewise if there is leak on any of the cooling system hose or the radiator, the same will happen.

Most Peugeots I know do have bleed screws for bleeding the cooling system. Those that dont have the bleed screws are designed in such away that as you are re-filling the system after flushing, air will be going out of the system as well, and there wont be need for bleeding the system.

Ikenna.

Ikenna351: @bigx

I forgot to ask. How fast is the spinning of the fan since you reconnected the fan to factory? Is the speed the same with when it was running constantly?

Why am asking is because if the fan is not fast enough, it wont push or suck heat out of the radiator. Hope no one has tampered with the fan relay.

Ikenna.

cretin: he cud also flush and steam wash the radiator in n out..and dirt clogs up n reduces the cooling surface area of the radiator

You guys hit it straight, Honestly we should push for an Auto Enthusiasts/Problems Sub-Forum where all these helpful posts would be moved to as you guys have really saved us a lot of money & headache from mechanics.

I just checked this evening and the issue was as you said, a leakage in my radiator, the heat shield was not properly fixed the last time the mechanic touched the car so it probably, with vibrations from the road, tore the radiator slightly,

I think I would also flush the radiator as cretin said as the fluid inside looks really rusty.

@Ikenna I think the fan still turns normally (same sound)

Thank You all so much.

bigx:





You guys hit it straight, Honestly we should push for an Auto Enthusiasts/Problems Sub-Forum where all these helpful posts would be moved to as you guys have really saved us a lot of money & headache from mechanics.

I just checked this evening and the issue was as you said, a leakage in my radiator, the heat shield was not properly fixed the last time the mechanic touched the car so it probably, with vibrations from the road, tore the radiator slightly,

I think I would also flush the radiator as cretin said as the fluid inside looks really rusty.

@Ikenna I think the fan still turns normally (same sound)

Thank You all so much.

The fluid looks rusty because you use water. Flush the rusty colored water out & refill with coolant. Even if you cant afford to fill the cooling system with coolant only, make it 70:30 (coolant -70% & water 30 %). Coolant acts as a lubricant to water pump & prevents the rusty color of fluid in the system. The rusty colored fluid in the radiator, will at some point, clogg radiator & corrode engine walls, which would blow up the head gasket when that happens. The use of water only in cooling system kills both the engine & its cooling system. So if your 307 cooling system takes 5 litres of fluid to refill, buy 3 litres of coolant (probably TOTAL cooalnt) & top up with 2 litres of water, while refilling after flushing. Once you refill with coolant, you will never see the rusty colored fluid in the system again & your water pump will last longer, & finally, no corrosion of engine walls.

Ikenna.

Thanx ikenna for the whole education. I've learnt a few things to apply on my bmw. I think i'l have to revert to the coolant stuff. Also,the car never overheated (only once that i didnt properly lock the radiator),i've removed the thermostat. I noticed that the car stays longer cold after starting the engine (at least what the guage tells me) than before. But no problems so far...

Ikenna351:

The fluid looks rusty because you use water. Flush the rusty colored water out & refill with coolant. Even if you cant afford to fill the cooling system with coolant only, make it 70:30 (coolant -70% & water 30 %). Coolant acts as a lubricant to water pump & prevents the rusty color of fluid in the system. The rusty colored fluid in the radiator, will at some point, clogg radiator & corrode engine walls, which would blow up the head gasket when that happens. The use of water only in cooling system kills both the engine & its cooling system. So if your 307 cooling system takes 5 litres of fluid to refill, buy 3 litres of coolant (probably TOTAL cooalnt) & top up with 2 litres of water, while refilling after flushing. Once you refill with coolant, you will never see the rusty colored fluid in the system again & your water pump will last longer, & finally, no corrosion of engine walls.

Ikenna.

I've always seen coolant in the car manual but I always thought it was a cooler way of saying water, lol . Can I get it at any Total filling station? And how much does it cost usually?

bigx:

I've always seen coolant in the car manual but I always thought it was a cooler way of saying water, lol . Can I get it at any Total filling station? And how much does it cost usually?

Yes, you can get it from any TOTAL filing station. The last time I bought it, it was N400 a bottle (1 litre).

Ikenna.

Ikenna are you resident in Lagos, Nigeria? Can you help with fixing a new thermostat, restore radiator fan connection, check cts and other things you outlined here?

Cruise-z:
Ikenna are you resident in Lagos, Nigeria? Can you help with fixing a new thermostat, restore radiator fan connection, check cts and other things you outlined here?

Would have loved to help. But I reside in Abuja, as my signature indicates.

Ikenna.

Oh! Thanks all the same bro. I am so so grateful.

I want to visit automedics located at LTV compound, Agidingbi Lagos. If anybody in this forum have used then in the past, kindly share your experience with us. I have a mechanic i have been dealing with for years; a trustworthy guy but i want a pro to handle this cos i want it done and extensively tested.