1999 V40T Engine Light/Cooling

donny_s18 · Post by **donny_s18** » 08 May 2017, 23:58

Greetings all!

Hoping someone here can chime in and point me in the right direction with my V40T overheating/ECU problem. I have done a search through this forum and google but to avail so if someone has covered this please let me know. Will do my best to provide as much information and detail as possible.

My 1999 V40 (turbo) overheated due to a busted radiator causing the car to come to a halt (dashboard engine lights all lit up)... engine fan came on at high speed during this time.

First thing i did was tow the car home and replaced the radiator, thermostat, spark plugs, engine oil, oil filter, coolant and followed by a burp/bleeding of cooling system. All cooling fuses look fine.

I took the car for a test drive around the block and so far so good... then car stalled mid turn and the "triangular" engine light came on.

Restart but the engine light stayed on. Drove around for approximately 10-15minutes and the temperature started rising! Switch engine off. Fan still not working!

Tested fans with direct battery contact and works fine.

I have reset the ECU by removing the batter terminal. Problem still present.

Connected a OBDII scanner and said "Mitsubishi Radiator sensor3 LIN comm."

I dont know what else i can do here besides running an aftermarket thermo fan switch. This will fix the fan problem but the engine light will remain present.

ANY help or suggestions is greatly appreciated!!

Donny
Sydney, AUSTRALIA

Post by **alschnertz** » 10 May 2017, 03:55

If you ran it so hot that it stalled out, my initial guess is that you blew a head gasket and/or warped the head.
Do a compression test before you sink any more money into it.

donny_s18 · Post by **donny_s18** » 12 May 2017, 08:46

That's a good idea.. thanks for the recommendation!
Assuming that side is fine any idea what may be a solution to my problem?

Post by **alschnertz** » 12 May 2017, 16:15

Not yet. Will wait to hear your results and think about proceeding.

Post by **alschnertz** » 13 May 2017, 04:38

You can also check for combustion gasses in the cooling system as a head gasket failure symptom.

donny_s18 · Post by **donny_s18** » 15 May 2017, 05:59

Cool.. Will check this out in the next few days.
Hey I really appreciate your input!

donny_s18 · Post by **donny_s18** » 05 Jun 2017, 01:39

Ok so.... just did a compression test and looks fine. Swapped relevant relay(s) and double checked all plugs associated with the cooling.

There are two fans of different sizes on this vehicle (larger black one and a smaller white one):

White fan on the RH side of the vehicle (which is "left" if you're looking at the engine bay from the front of vehicle)
Black fan on the LH side of the vehicle (closer to battery)
**i dont refer to driver or passenger side as it might confuse those that live in another country with different driving localities.

I turned the engine on (A/c off) and let it idle til the temp gauge went to approximately half way which the smaller/white fan switched on then off. Finally a fan switched on when needed .. but is it the right fan??? I was under the impression the smaller (white) fan was only for A/C and the larger fan was for cooling the radiator. Reason I assumed this is because the white fan always kicks in when i turn the A/C on.

I now have two questions:
1. Does anyone here know the role of each fan?
2. Where should temp gauge normally sit at? (slightly below or above halfway) mines is currently sitting just above halfway up.

Many thanks for your time to read this and apologies if I'm not getting straight to the point.

p.s. the engine light is still on but will try to do a reset.

difflock54 · Post by **difflock54** » 05 Jun 2017, 03:20

Check the wiring connections to the coolant temp' sensor are not loose or dirty and also likewise the connections to the radiator fan.

donny_s18 · Post by **donny_s18** » 05 Jun 2017, 04:15

difflock54 wrote: ↑05 Jun 2017, 03:20 Check the wiring connections to the coolant temp' sensor are not loose or dirty and also likewise the connections to the radiator fan.

Hi Difflock54, good idea... do you know how many coolant temp sensors are on this motor? There is one beneath the thermostat that i will recheck. All radiator fan connectors are fine (checked with a multimeter).

anyone know what this green triangle light means ? OBD scanner shows P1542 which according to various google searches mean A/C System High Pressure High Temperature or emission controls (?)

Anyway i'll continue with the elimination of issues and continue to post in case this information is useful for others.

difflock54 · Post by **difflock54** » 07 Jun 2017, 20:07

Click the link below.
Its a forum thread which explains the warning light your getting.

http://www.volvoforums.org.uk/showthread.php?t=20505