914 subaru water pump over heating Options

[jeepguy06]

hey guys

so I have a ej205 in the 914 and when sitting at lights in traffic it starts to overheat. I watch the temps clime to 208.4 at times if not hotter. I find that revving the car to 3k and keep it for about 30 seconds to get the coolant moving the temps will then drop down to 203. once i start moving and driving the temps drop all the way down to 197.6 I just feel that the water pump is not able to move the water from engine to radiator all the way in the front. has anyone else had issues like this and how did you repair them? add another water pump that's electric?

[Root_Werks]

Haven't ever owned an H2O converted 914, but also haven't heard of folks who have done builds here say the stock WP's weren't enough. I'm wondering if the radiator and/or cooling lines are undersized?

[Bartlett 914]

I have a 91 VW Camper with a 2.5 Suby. My waterpump is able to pump coolant a longer distance than you would have in a 914. My coolant lines are of sufficient diameter without too many restrictions. My radiator is new. There are a couple of known issues to consider. It is important to use a Subaru thermostat. Aftermarket ones should be avoided. The other issue is with the heater circuit. In a Subaru, coolant flows thru the coil at all times. Heat is controlled with a flap and not by restricting coolant thru the coil. This coolant flow is important as it flows by the thermostat allowing proper thermostat operation. Overheating can occur when this flow is stopped. The thermostat is low on the motor. Without a coolant flow, temperature near the bottom of the engine is cooler than at the top of the engine. The thermostat thinks the motor is cool and closes so no flow to the radiator.

[914pipe]

I have a 91 VW Camper with a 2.5 Suby. My waterpump is able to pump coolant a longer distance than you would have in a 914. My coolant lines are of sufficient diameter without too many restrictions. My radiator is new. There are a couple of known issues to consider. It is important to use a Subaru thermostat. Aftermarket ones should be avoided. The other issue is with the heater circuit. In a Subaru, coolant flows thru the coil at all times. Heat is controlled with a flap and not by restricting coolant thru the coil. This coolant flow is important as it flows by the thermostat allowing proper thermostat operation. Overheating can occur when this flow is stopped. The thermostat is low on the motor. Without a coolant flow, temperature near the bottom of the engine is cooler than at the top of the engine. The thermostat thinks the motor is cool and closes so no flow to the radiator.

(IMG:style_emoticons/default/agree.gif)

Like he mention. Just capping the heater lines won't work. You need the loop otherwise it can air pocket and cavitate.

Hope that helps.

[theer]

Also, keep checking for air in the system. The long coolant lines going low and high create lots of places for air to get trapped. Once the system is full, cooling has never been a problem- even in 90+ degree stop & go traffic. I have an electric coolant pump, so can comment on the adequacy of the stocker.

[Robarabian]

My car runs at a pretty consistent 165 degrees. Stock water pump. Air pockets are horrible, so make sure it is purged, and then purge it again. I run dual SPal fans that run constantly, not on a temp switch. I do notice that when I am really on it, the temp falls significantly as the water pump flows alot of volume. A stock pump is sufficient.

I use a lower temp thermostat as well so it opens sooner.

[Chris H.]

You definitely do need a loop of some kind for startup, otherwise there is no coolant circulating at all until you hit the thermostat temp. Doesn't need to be much, just enough to move the coolant through the engine in a loop.

The stock water pump should keep up fine. I agree with the group that you probably have an air pocket(s) somewhere, or the cooling system setup needs some tweaks. A sealed system that is pressurized will bleed itself after a few warm up/cool down cycles. I've been running an EG33 with stock water pump for almost 10 years and the only issues I had were at the very beginning (air pockets due to a bad air bleeder connection on the radiator that prevented air from getting out at the top). Once you get the system bled properly it should stay cool.

[jeepguy06]

Haven't ever owned an H2O converted 914, but also haven't heard of folks who have done builds here say the stock WP's weren't enough. I'm wondering if the radiator and/or cooling lines are undersized?

I did the Toyota Celica gts radiator that a few has used. Also used 1 1/4 lines from the front to the back.

[jeepguy06]

I have a 91 VW Camper with a 2.5 Suby. My waterpump is able to pump coolant a longer distance than you would have in a 914. My coolant lines are of sufficient diameter without too many restrictions. My radiator is new. There are a couple of known issues to consider. It is important to use a Subaru thermostat. Aftermarket ones should be avoided. The other issue is with the heater circuit. In a Subaru, coolant flows thru the coil at all times. Heat is controlled with a flap and not by restricting coolant thru the coil. This coolant flow is important as it flows by the thermostat allowing proper thermostat operation. Overheating can occur when this flow is stopped. The thermostat is low on the motor. Without a coolant flow, temperature near the bottom of the engine is cooler than at the top of the engine. The thermostat thinks the motor is cool and closes so no flow to the radiator.

(IMG:style_emoticons/default/agree.gif)

Like he mention. Just capping the heater lines won't work. You need the loop otherwise it can air pocket and cavitate.

Hope that helps.

I went ahead and ran the heater core lines into the cab of the car and put in a small heater core with fan to put heat into the cab of the 914.

[jeepguy06]

Haven't ever owned an H2O converted 914, but also haven't heard of folks who have done builds here say the stock WP's weren't enough. I'm wondering if the radiator and/or cooling lines are undersized?

I did the Toyota Celica gts radiator that a few has used. Also used 1 1/4 lines from the front to the back.

[ogdougy]

No ej20 in 914 experience but plenty of ej experience.

The EJ even in Subarus were a bitch to burp all the air out of the coolant system. And with the normal radiator mounting i have seen for the 914 at the front, the cap of the radiator sits lower than the motor.

If you have a steep enough driveway. Park it to make (at least) the cap of the radiator the highest point in the system or jack the front up with jackstands or ramps. Burp it that way.

[L-Jet914]

I've worked on EJ's as well. I think the best invention to come out for EJ's, FA's is the vacufill system that pulls the cooling system into a vacuum, prime the fill line shortly, pull another quick vacuum, then fill the cooling system. I ran into many an issue with EJ25's in the late 90s to mid 2000s outbacks. Fans would come on high speed and I only got cool air through the radiator. I had to burp the system multiple times. As for the VW Vanagons which I have also worked on, they have a bleed valve on the top of the radiator. Before the vacufill systems arrived we would raise the front of the Vanagons and burp the cooling systems that way until all of the air was out with heater on full hot. I have the Snap-On version where I work but AirLift was the first version I heard of when the tool came to the market. I use it on the occasional MR-2's that come in and the FR-S/GT 86's (Subaru BRZ) and all of the other Toyota's that I work on at the dealership. Cuts cooling system bleeding time down significantly. You can also put a coolant fill funnel that attaches to the radiator cap/neck to do a final check if you like. I tend to slightly overfill coolant reservoirs as I know it will burp a little more after the service.

[L-Jet914]

This is the tool.

[jeepguy06]

I've worked on EJ's as well. I think the best invention to come out for EJ's, FA's is the vacufill system that pulls the cooling system into a vacuum, prime the fill line shortly, pull another quick vacuum, then fill the cooling system. I ran into many an issue with EJ25's in the late 90s to mid 2000s outbacks. Fans would come on high speed and I only got cool air through the radiator. I had to burp the system multiple times. As for the VW Vanagons which I have also worked on, they have a bleed valve on the top of the radiator. Before the vacufill systems arrived we would raise the front of the Vanagons and burp the cooling systems that way until all of the air was out with heater on full hot. I have the Snap-On version where I work but AirLift was the first version I heard of when the tool came to the market. I use it on the occasional MR-2's that come in and the FR-S/GT 86's (Subaru BRZ) and all of the other Toyota's that I work on at the dealership. Cuts cooling system bleeding time down significantly. You can also put a coolant fill funnel that attaches to the radiator cap/neck to do a final check if you like. I tend to slightly overfill coolant reservoirs as I know it will burp a little more after the service.

I got the bucket set up that goes on the radiator cap on the fill resivor that's next to the intake manifold. I also had an extra hose line on the radiator u got and used it to bleed the air out of the front part of the system but will have to check it again.

Thanks for the ideas.