Possible Air In The Coolant Lines?

[Redmanndisco]

Hey Guys

04 Disco

Recently i replaced my engine myself with a new performance engine. After putting everything back together and driving about 250 miles with no issues a small issue has come up.
I was driving on the highway when i started to smell some coolant and then realized that the temp gauge was slowly climbing, i put on the heat on max fan and max heat and the temp gauge started to drop...phew!
So this is where it gets interesting, finally when i did get home i started to poke around and noticed that the "upper" vents where blowing cold air but the lower vents were blowing warm air (temp was set at 70 on both sides) but when i set the temp to max heat it was blowing hot air in the upper and lower vents, only when the temp was set at lower temp was it blowing 2 different temperatures.
Eventually i made my way to the passenger side and noticed some coolant on the floor which is what i guess i smelled on the highway about an hour before. I removed the lower panel under the blower motor and saw some coolant from the upper most area as well as a little coolant from the 2 heater hoses under the dash, as well as a few other spots.

Does this sound like an air pocket issue that just moved to the heater core?
Why would it blow both hot and cold air?

Any insight on this is much appreciated.

Shavit

 

[jeffro0502]

Hey Guys

noticed some coolant on the floor

leak

 

[akronk1]

I recall another thread where on of the replies was there is a possibility if you try and twist off your heater hoses instead of cutting them, before removing, you can damage the metal lines going throught the firewall to the core and cause a leak. Think this was for a D2 but then again might have been for a RR.

 

[Redmanndisco]

Thanks akronk1

After reading your response i looked at the 2 heater hoses in the engine bay and did notice some coolant on the wall dripping down the fire wall.....so that could be where my leak is coming from.

Do you happen to have the link on the post you mentioned that you had read?
just want to read up on it

Thanks

 

[bullcrew]

You could bypass the heatecore and run it to make sure it its not leaking anywhere else this would keep it running with no OH issue and give you a little time to diagnose o-rings, hoses or hole in heatercore

Just a thought I'm going through this now.

 

[listerdiesel]

The two pipes that run through the bulkhead are not the actual core pipes, they join to the core via two o-ring joints on the end of the core, not a terribly good bit of engineering.

I don't think that the late Disco's changed the arrangement, or that the versions with aircon are different to the basic models without.

Microcat is not very good at illustrating the assembly, so I can't post a picture.

Peter

 

[akronk1]

Sry I don't remember the thread title, think it was in 2011. Perhaps one of those posters can chime in.
Peter does the d2 use the same o-ring setup as the rr with one screw holding o-rings in place?

 

[jymmiejamz]

A DII can blow hot air from the floor vents and cold air from the face level vents.

 

[listerdiesel]

Sry I don't remember the thread title, think it was in 2011. Perhaps one of those posters can chime in.
Peter does the d2 use the same o-ring setup as the rr with one screw holding o-rings in place?

I believe it is.

Here is a picture of the standard heater core ends, this one is in my spares store

Those pipes are slightly angled away from each other.

Peter

 

[Redmanndisco]

So a quick update to anybody who was following this..............

The issue was in fact the heater hose where it attaches to the hose on the firewall.

The reason that it was leaking only sometimes and not all the time was because it only leaked when i really hit the throttle (a sudden pressure increase) which caused the coolant to leak out, and down the fire wall and onto the floor in the truck

I accidentally reused one of the old hose clamps which had no more clamping power so only under higher pressure it leaked. when i went to remove the old clamp i was able to remove it without any pliers!...ops!
$1.99 later for a set of 2 hoseclamps....problem solved.

thanks guys!

 

[RR1]

For what it's worth - I had the same issue the past 2 weeks after having the hoses replaced a month ago. It leaked every now and then, leaving a small puddle under the truck right under the front driveshaft. Sometimes it would leak...sometimes it wouldn't... They replaced the hose and clamp and now it seems fine. I also replaced the coolant cap just in case there was a weird pressure issue.