Left my 95 Disco setting down behind my house for a few days took it down there had a bonfire/camping weekend with it. After leaving it down there due to a little drinking letting the battery go dead I finally retrieve it like two days later. Well pull I drive it down the road and give it a chance to charge the batter up a little before I park it so it is up to its normal operating temp which is a little on the low side of what most people like 156*f but thats not the issue. As I pull in the driveway I hear bubbling like air coming up through water, so I listen closer and realize that it is coming from directly behind the Cd player. I give it a little fuel and you can hear it go away and then after probably 30 sec maybe a little less it comes back. I check the coolant tank and it is exactly where I filled it up to when I change the thermostat, and installed the new clutch on the fan a few weeks back. Has anyone else had this issue or dealt with something like this? Seems strange that it would be a air pocket as the vehicle has been driven and lightly wheeled, along with the fact it has no overheating issues

 

There could be a very minor leak somewhere, slightly low on coolant, OR, you could have the beginnings of a head gasket leak. Often times a head gasket will seep and over time you'll hear bubbles in the heater core. Then one day, poof, you have white smoke out the tailpipe. But start with the thermostat (it's running way to cool) otherwise it'll damage the engine over time, then ensure there are no leaks.

 

Hmm, may have to pay closer attention to mine. Makes a similar sound, more like a slosh in the heater core. It only sometimes does it, and usually only when I rev the engine for the first time after cold start. It occurred to me that coolant must be low, but head gasket had not crossed my mind.

Thanks for the "heads up" (no pun intended).

 

That is not a good diagnoses to hear, but kinda what I was thinking at the same time. If the head gasket is leaking it must be letting compression into the water jacket instead of using coolant. Guess I will be adding bolts and gaskets to my long list of parts I am in need of. Might as well have the guides and valve seats checked while the heads are off.

 

When was the last time you really, really did a proper air bleed of the coolant system? just having the res. at the proper level is not gonna do it.

Then get someone to pressurize the system and look for leaks.

In your mind you're already buying a HG job? Please start with the basics...

**Edit** did you ever perform a test on the Temp sender to make sure IT is functioning properly. How are you getting that temp measurement? Do you still have the hot start problem?

 

yes, you need to properly bleed you coolant system not to mention your are probably low on coolant and the leak could be something as simple as the crappy LR hose clamps coming loose. replace them all with

 

I bled the system twice since I have done the thermostat install, had plenty of experience with GM systems that didn't like to let the air out as well. As for pressurizing the system that I have not done, it has been on my list of things to check though. I have got an order ready for all the temp senders/sensors but haven't placed it yet trying to get everything at once since it has to be shipped. As for the temp readings I have an infrared temp gun I use on my race car for tuning purposes. I have taken reading from both head surfaces, radiator tanks, and the thermostat housing. The hot start problem could be slightly related to a bad reading FTP but after having to jump start the truck the other day I am pretty sure it has some ground or battery cable issues. I have been so busy working have not had time to really take care of anything maintenance wise. I have all of next week off and can hopefully get it ready for some winter time fun

 

well then, I guess you "really, really" have bled the system.

At this point I'm just running through the system... Have you given the in / out heater supply hoses (over the right Valve cover) a good look? Those tend to leak when old and allow air into the system as it cools. Plus, they are the coolant lines immediately before and after the area you say the sound is coming from. This is an easy leak to spot since it'll stain the cover. I'm sure you would have seen something though.

Sounds like you've got it under control. And by the way, you own an old land rover.... you do not have next week "off".

Let us know how it goes.

 

I hope it is all under control, luckily I picked this vehicle up just for something to play with in the woods and maybe drive around local a little. It is definitely a different world when it comes to the mechanic side of things. Got a lift ordered for it, already have tires setting here waiting to go on. Just had it for maybe a month or so I really like the capabilities they offer in stock form can't wait to see what it will do with some real tires on it and a few more inches of altitude

 

Looks like I found the leak today, went ahead and put some more antifreeze into the system to make it safe for the 20-30* weather we have got on the way. Looks like the rear of the valley pan under the intake is leaking and running down the bellhousing to the rear of the tranny. That also explains how the coolant tank stayed full and still got low on coolant it was actually running out the rear of the engine. Should have parts to fix this in a few days hopefully I can get them overnight and not have to waste my week off