Overheating EA-81 Engine

[cawain]

Hi, I have a EA-81 engine I have adapted to a VW transmission. (Trike) I bought the engine from a guy that said it was re-built. I don't doubt that. However I had problems from the start getting it to run properly, and I think the thermostat might have been stuck closed. What I have now is an engine that is over heating. Runs great, idles smooth But blows coolent back out the radiator. It has a new radiator, thermostat, radiator cap and waterpump the cooling fan kicks in at about 200 on the temp gage. I am thinking that I have a blown head gasket or a cracked head. It seems that I have exhaust getting into the waterjacket. I have no water in the oil, or oil in the water. I also have no milkey condesation inside the oil filler. If you leave the radiator cap off the coolent will push out of the radiator as it heats up. Another reason I feel it is getting exhaust in the cooling system.

Now all that said. How do I tell which head is bad? On the old Olds diesels (V-8) I would un-hook the belts, remove the thermostat housing, start the car up and watch which direction the bubbles came from to tell which head was bad. Tried doing that with the EA-81 and couldn't see any bubbles. But after it warmed up good coolent filled the intake an gushed out. So any one have any other ideas?

Thanks in advance, Carl

[hatchsub]

I had a similar problem with my EA81. It ended up being something simple. I needed a new radiator cap. When the coolant heats up it does go up and will overflow with no cap. If you dont see any bubbles in the coolant however im not sure you have blow headgaskets. I would try doing a compression and leakdown test to see whats going on and also spend the 5 bucks on a new cap and see what happens. These engines dont have overflows so if the cap is not holding the pressure it needs to then it will boil over.

[Durania]

I had a similar problem with my EA81. It ended up being something simple. I needed a new radiator cap. When the coolant heats up it does go up and will overflow with no cap. If you dont see any bubbles in the coolant however im not sure you have blow headgaskets. I would try doing a compression and leakdown test to see whats going on and also spend the 5 bucks on a new cap and see what happens. These engines dont have overflows so if the cap is not holding the pressure it needs to then it will boil over.

 

+1

 

Also make sure that you are using a Subaru thermostat and gasket. The ones at the parts stores are garbage in comparison.

[cawain]

Durabia, Thanks for your reply. I have a new cap (checked it and it holds 13lbs.) I did a compression test and # 1 & 3 cylinders are about 10 lbs lower than 2 & 4. I haven't been able to get a leak down tester yet to do a leak down test. Cylinders #1 & 3 showed lower compression after the engine was warmed up. # 2 & 4 were the same warm as cold. So I am thinking that maybe the right head has a bad gasket or a crack in an exhaust valve seat. I think I will pull the right head tomorrow and have a look at it. If my findings are inconclusive, than I will get another engine ready to go on the trike.

Thanks again, Carl

[vatriiker]

So what did you find out. any pictures of the trike ? planning on converting my trike to subie as well

[cawain]

The main problem I found was the rebuilt water pump I put on was faulty. The impeller was loose on the shaft. Fixed that with a NEW one not re-built. Next, Not enough air flow through the radiator. Re-mounted the radiator for better air flow, and changed the fans to suck air through the radiator to the rear. It is still not running as cool as I would like. So I mounted an oil cooler from a EA-81 turbo today. Hope to give it a test run tomorrow. I am going to get a 4core radiator made up to try next. If I keep my speed at around 55 to 60 it cools good. Temp stays around 220 on my guage, fan cycles off and on ok. I have a second fan I can turn on manually. At 65 to 70 the temp goes up around 250 and dosen't come down very well when the fan kicks on.

I am building another trike and I am going to use 2 goldwing radiators. I will mount them forward of the engine with plenty of ventilation. They will be hooked in parallel.

I really like the subaru engine. It is very smooth and has a great deal more power than the 1600 VW engine I had before. I think that modifing an older tike causes a lot more problems than building one from scratch. Having a trike that is already built I was limited on my radiatior installation. I will try to get some pictures tomorrow. Carl

[Twitch de la Brat]

You didn't exactly post whether or not the losing coolant issue was gone, so I

would check your intake manifold gaskets, as you mentioned your intake was

filling with coolant.

 

Also, a radiator flush would probably help your cooling problems.

 

Good luck getting your Trike running reliably

 

Twitch

[cawain]

In the process of working on this engine I replaced the head gaskets, and manifold gaskets just in case. I also found the bad water pump at this time. The radiator is brand new. Clue to bad water pump is: The bypass hose that goes normally to the heater and back to the manifold was not getting HOT when I had a faulty water pump. I let that one slip by me. I.E. no movement of coolent durning warm up.

Trike is a 2001 based on a VW bus rear suspension. It had a 1600 DP engine before I put in the Subaru. Adaptor is from Kennedy eng, and bolted up with no problems. Engine EA-81, Transmission, VW bus, Front end , built by me.

My daughter and I are planning a ride to Alaska in Aug. I will be rideing this trike and she will be rideing a VW trike I built for her. Thanks for all the interest and help I have received from all you folks. You guys and gals have are the greatest. Carl

Edited July 1, 2010 by cawain