Fb15 Ex-Saloon Yr2000 Engine (Qg15De) Problem

[Lahiru85]

My dear friends, experts,

I have a FB15 Ex-saloon 1500cc automatic transmission car (yom2000) and bought 2 years ago. I have done 8000km up to date and the car was stopped suddenly while driving on the road with “crees crees” sound. When the bonnet was opened by me, noticed that the belt connecting alternator was smoking. I have turned off engine and carried to the garage that was familiar me. Mechanic checked the engine, cooling fans, radiator.

The engine was raised by him and boiled up also fans were not automatically turned on. Again the engine was raised with directly connected fans and again boiled up. He told me, the engine’s gasket, thermostat sensor should be replaced and both parts were replaced with Nissan genuine after facing engine head. After replacing gasket & sensor, he told me, problem originated from faulty AC compressor because the engine was turned off automatically when AC switched on. Then AC compressor was replaced and the problem was solved partially.

But coolant was leaked out from water pump if the engine was raised with out direct fans (fans were turned on automatically via sensor. But it was not turned on before boiling starts). He checked water pump and told me, it was a good one. To day I have done 10km with directly connected fans & AC and noticed coolant was leaked out from water pump and top side of radiator (but radiator plastic tank is not faulty one). Then I raised directly connected fans, removing radiator cap. I noticed that no leaked coolant on water pump. Then I raised directly connected fans+AC, removing radiator cap. I noticed that no leaked coolant on water pump but the coolant was run out slowly from radiator tank opening.

please help me to solve this problem.

[The Don]

It was a little difficult to followed. I think when you say raised you mean raced.

If a car starts to boil and the fans come on on time, the first thing to suspect is blockage of the water lines. This could be inside the radiator or on the lines themselves. This should be checked out. The radiator can be cleaned manually by any radiator place.

I don't understand what you mean when you say you see water leaking from the water pump. Explain please, because that usually indicate a failed water pump.

[Rumesh88]

Your first symptoms were those typical for a seized up compressor. I do not find any reason to go behind the radiator system to solve this unless of course there were two separate issues. It is clear from your last observation (ie no apparent leak when the radiator cap is opened. I hope this is what you meant) that you have a leak closer to the water pump. It should not be difficult to trace and as Don says above may indicate a faulty pump or a crack/leak in a hose.

[Amila_Silva]

Agree with Don.

It seems that the best first thing to do is to remove the radiator and check whether it is blocked by corrosion. If you take the car to a radiator & AC repair shop, they can perform a pressure test on the radiator too which detects for leakages. You can even remove hoses and test for leakages and send high pressure water through the engine and hoses to remove dirt or any matter which has blocked the water circulation.

If there are any faults exists for above tests you have to fix them first. Then, replace coolant and make sure there are no air bubbles exists in the cooling system. Once you replace coolant, and when the engine is cold, start the engine with radiator cap off and inspect whether there are air bubbles popping up. Since you have replaced the head gasket and plate the cam head, there should be no air bubbles.

Since you have replaced the thermo switch which turns on the fans, I believe it is not faulty. But how about the thermostat? Check whether your car has it and if so check whether it is faulty

[Lahiru85]

Yes friend, raced (via accelerator)

After replacing gasket, the car does not start to boil with directly connected fans but the coolant runs out slowly from radiator cap opening (when the cap was removed).

Coolant does not leak from water pump when the radiator cap was removed (leaking happens if radiator cap was fixed to radiator. If the water pump is faulty, coolant should leak any time, isn’t it? my understanding is the highly pressurizing the coolant circulating system above working level.

Radiator was cleaned manually but the problem is still there.

As you said, water lines could be blocked (you mean water lines of engine, isn’t it). This blockage may initiates to pressurize the coolant circulating system.

Please tell me, which steps should follow my mechanic to solve this problem. If not, who are very good engine expert mechanics that can solve this problem? I’m in ja-Ela area and think my mechanic has no solutions above this level. Please advice

[Rumesh88]

It is normal for the coolant to overflow from the radiator cap if you remove it and run the engine. Also it is normal for minor leaks to show up only when you close the cap for then only the pressure inside the system build up sufficiently to cause a leak. As Amila has advised best thing is to get a pressure check done to identify the leak.

[The Don]

Ok I think I will try to sumarise your problems

1. Your engine boils if the fans are run on normal operational mode via the fan thermostat. The solution now is to run both fans (Radiator and condenser) directly all the time? Is the radiator the original radiator of the car (as in the right size?). Also is the thermostat you recently replaced the correct one for the car? When replacing things like thermostats and thermostatic switched it pays to purchase them directly from the agent, as putting the wrong one in will upset the entire system.

2. When you keep open the radiator cap on a warm engine water spills out. This is normal, as the heat causes the water to expand, hence why the radiator cap has a spring in it to keep the pressure at a pre determined level. If the pressure goes beyond this level, water will expand into the expansion bottle connected to the radiator.

3. You observe a coolant lean from near the pump under normal operation (radiator cap closed, both fans running and engine warm)? This is abnormal behaviour as the coolant should start flowing into the expansion bottle before the pressure gets too much for the system. There is possibly an issue with your water pump seals, so replace if you haven't done so recently.

[Lahiru85]

Dear Friends,

1.1 Both fans directly all the time

1.2 No thermostat during last two years (removed)

1.3 Thermostatic switch (sensor) replaced by a brand new Nissan genuine one (it is not a low cost Japanese substitution sensor )

2 Can this happen for 10km of run with directly connected fans? In addition to that coolant leaks from interface connecting radiator plastic tank (not the expansion bottle) and aluminum tank (radiator) if radiator cap was closed. But the radiator plastic tank has no crack or any damage. Can this happen due to faulty radiator cap?

3.1 //You observe a coolant lean from near the pump under normal operation (radiator cap closed, both fans running and engine warm)?// Yes

3.2 ok, I’ll change water seal

A radiator mechanic inspected the problem and told me that bolts of engine head should be tighten further because small leak there. But it is not done yet. Also I want to find very good mechanic to troubleshoot this problem after 13^th september.

I have a doubt regarding this problem whether this is a problem in engine head itself. I spent Rs.50k up to now regarding this problem and have a doubt of replacing engine and feared.

[The Don]

Dear Friends,

1.1 Both fans directly all the time

1.2 No thermostat during last two years (removed)

1.3 Thermostatic switch (sensor) replaced by a brand new Nissan genuine one (it is not a low cost Japanese substitution sensor )

2 Can this happen for 10km of run with directly connected fans? In addition to that coolant leaks from interface connecting radiator plastic tank (not the expansion bottle) and aluminum tank (radiator) if radiator cap was closed. But the radiator plastic tank has no crack or any damage. Can this happen due to faulty radiator cap?

3.1 //You observe a coolant lean from near the pump under normal operation (radiator cap closed, both fans running and engine warm)?// Yes

3.2 ok, I’ll change water seal

A radiator mechanic inspected the problem and told me that bolts of engine head should be tighten further because small leak there. But it is not done yet. Also I want to find very good mechanic to troubleshoot this problem after 13^th september.

I have a doubt regarding this problem whether this is a problem in engine head itself. I spent Rs.50k up to now regarding this problem and have a doubt of replacing engine and feared.

Hmm, if there is water leaking from anywhere in the radiator when the cap is closed, then the radiator needs to be repaired. If its leaking from the top tank, either the glue used to connecting the top tank to the core has become undone. This could have happened if the radiator was cleaned recently as they remove the tanks before cleaning.

I think it sounds like your engine seal between the head and the bottom end is not correct, or as the other mechanic suggested when the head gasket was replaced the head was not set properly and the head bolts tightened to the correct torque.

As Rumesh mentioned before do the small things first. If the radiator is leaking get that repaired.

Pressure test the water lines and identify any leaks or blockages. That will give you a clue as to where the problem lies.

When this guy replaced the head gasket, did he use gasket market on top as some guys do? With metal head gaskets you should just face the bottom and the head, line it up and set the head and tighten the bolts in the correct order to ensure a good seal. Else the water lines will not line up properly and water and oil may leak into places they shouldn't.

If the current guy has no answers take it to another mechanic.

After the main issue is resolved, replace the thermostat and revert the fans to run off the fan circuit via thermostatic switch. Else you get the opposite problem of engine running too cold.

[Lahiru85]

Thank you my dear friends for valuable advices. I'll come back to you after 14th september

[aps]

Dear Friends,

1.1 Both fans directly all the time

1.2 No thermostat during last two years (removed)

1.3 Thermostatic switch (sensor) replaced by a brand new Nissan genuine one (it is not a low cost Japanese substitution sensor )

2 Can this happen for 10km of run with directly connected fans? In addition to that coolant leaks from interface connecting radiator plastic tank (not the expansion bottle) and aluminum tank (radiator) if radiator cap was closed. But the radiator plastic tank has no crack or any damage. Can this happen due to faulty radiator cap?

3.1 //You observe a coolant lean from near the pump under normal operation (radiator cap closed, both fans running and engine warm)?// Yes

3.2 ok, I’ll change water seal

A radiator mechanic inspected the problem and told me that bolts of engine head should be tighten further because small leak there. But it is not done yet. Also I want to find very good mechanic to troubleshoot this problem after 13^th september.

I have a doubt regarding this problem whether this is a problem in engine head itself. I spent Rs.50k up to now regarding this problem and have a doubt of replacing engine and feared.

1. change thermostat

2. change radiator cap