I'm having an issue relating to the cooling system on my 1999 Discovery 1. It started about a month ago when I noticed a gurgling sound when starting the truck. I researched and discovered that it is a sign of air in the cooling system. I noticed I was loosing coolant at an increasing rate so I started topping off the car almost daily, which is about 20 miles for me, with distilled water. I did not see any signs of water in my oil so I decided to dig into the motor and replace the intake valley gasket.

I used the MFI engine section from the RAVE manual. I had trouble figuring out if that was the correct engine section in RAVE. I have a 4.0 V8 with an SD badge on the body. The motor has the same ram housing set up but in the manual it shows 3.9 on the plenum, so please correct me if that was the wrong spec at 38Nm. I used a FELPRO gasket.

After I did that work I am still seeing my coolant "mysteriously" disappear as well as spiking temperature gauge. my plan this weekend is to;

1) Re-torque the intake manifold bolts
2) replace the thermostat and top radiator hose.
3) Fill the system properly with 50/50 coolant mix rather than just water.

I need some advice from you guys as I'm not sure what is going on here and don't have much experience wrenching on Land Rovers

Is it a bad idea to run just distilled water in the cooling system before of boil over?
Am I looking at the wrong torque specs for my intake manifold?
What is the best way to properly purge all the air out of the cooling system?
Is this all a waste of time because it's a blown head gasket?

 

I'm willing to bet good money that you have blown a head gasket. This is fairly common for these trucks.

There are many many threads on head gasket replacement. It is not a super difficult job, but it does involve a great deal of wrenching.

If you are in North America it is most likely that you have the V8 4.0 SFI engine.

This is a fairly good thread for those folks staring down a head gasket job for the first time...
https://landroverforums.com/forum/di...ree-way-59520/

And another....
https://discoweb.org/showthread.php?...ht=head+gasket

 

Walt nailed it - Head Gasket.

Gurgling in the heater core is the give-away. Just bite the bullet and do it. You've been running on borrowed time anyway ...might as well do it now in a planned fashion rather than wait and be stranded somewhere when the head gasket goes completely. What happens is the head gasket layers rot and air seeps between the layers overnight as the engine cools into your system. I had a car that was that way for years and then one day it finally 'went'.

 

Darn. Mark, Walt, thanks for the advice. I was able to get the valley gasket replaced in 3 days. Sounds like that's almost half the work. I'm seeing what my options are for machine shops around here and where I can do this work. More Importantly, what will get me to work while it's being worked on.

I do have some more questions. I am in North America, the SFI section in the Rave manual has much less info than the MFI section. Especially for the intake section. The Rave is just so awkward to navigate. Can anyone point me in the right direction for torque specs for the intake and heads and valuable pages for removing the heads and anything before? Like I said, I got the intake off and I'm pretty confident I can get that far in a good afternoon.

Thanks for the help so far, I'm pretty sure I can get this work done on my own with good planning. I'll just be riding a motorcycle rain or shine for a week or two!

 

You know what .... if it's just gurgling and not blowing any white 'smoke', it could last years in that condition. I'm not saying it WILL last years, but it's typical of a deteriorating head gasket. What you should see once you get the headgasket in your hands is a rotted or weak area at one of the water passages and another passage -- most likely the cylinder seal ring if you look with a very close eye. I owned a Lincoln Continental a long time ago that did this for a good 3 years (who know how long before I bought it??). Then one day my wife headed off to work, and was back in 10 minutes with a giant cloud of white smoke behind her. We knew our day was coming because the symptoms becoming progressively worse. She knew to keep an eye on things and didn't panic. We have backup vehicles though so it wasn't too bad and I just laughed when she came driving back in!!

My 98 Disco has been doing the same thing since the day I bought it ...some 9 years ago, and who knows how long before that! I keep an eye on the oil and coolant level. It hasn't consumed much coolant like you reported, but I do need to add some every once in a while. It's not may main driver and I don't drive it a ton, I'm just going to ride it out. Heck, I drove it across country from S.F. (I'm in WI) when we bought it ....and even went on 2-3 family trips out West with it -- 1500 miles away deep into the mountains 12,13,14,000 ft high ...Moab a couple times -- how smart is THAT!! I wasn't too freaked out because usually the symptoms tend to get progressively worse as the gasket continues to degrade, then one day BAM! (well, it actually doesn't make any noise). But guess what, 2 days ago I started the Land Rover and backed it up to move my trailer and what did I see? .... a small cloud of white smoke (steam actually) coming out the exhaust for the first time. It went away after 5 minutes. That tells me that the metal ring on the head gasket that seals around the cylinder has degraded sufficiently between it and a cooling passage, and now, actual coolant is starting to leak into the cylinder. But it's just a little, probably after shut-off and a few drops are getting into the cylinder. When I start it up it blows out into the exhaust and continues to burn away as the exhaust gets warm/hot and makes steam ...until it's all burned away. But the point is, it's been a good run (8-10 years) but the end is near for that headgasket and I won't be going on any family trips with it until the H/G is replaced.

My other point is: I wouldn't let the gurgle throw you into a panic just right now, unless you're noticing worse symptoms. A lot of people experience that gurgling for years. I'm not saying it can't let go tomorrow (it 'could'), you just don't know when your number will be up, but chances are very good you can plan this out for a more convenient time, just keep an eye on the coolant and oil ...and tailpipe. I'd plan things out, get all your parts, figure out where is a good machine shop locally and their prices and turn-around time. Check with some of the car shops in town, where they take their engine parts. Then wait until July if you have some time off over the 4th of July to put it back together. Or better yet, remove the heads the weekend BEFORE the 4th, take them to the machine shop and have them back so you can put it together over the weekend of your choosing. Maybe it's Labor day?? Not as much rain in late summer. The other option is to wait it out like me, and who knows, maybe it'll be 2-3-5 years until it let's go and you get the big white cloud. Maybe by then you'll have pulled your hair out enough and ready to move on to a Jeep, H3 ...or LR3.

As far as the job goes, you should be able to have the intake and heads off in a couple hours. Lay a big piece of cardboard in the back and just circle and write down on the cardboard which cluster of bolts goes here and there if that will help you. It's a pretty straight-forward job if you have decent mechanical skills and actually kind of fun if you can take your time. Since you already know how to do the intake the job should take 30% less time.

You're going to need to get new head bolts. You can buy a whole kit ...heck, ebay has some great prices. You might as well buy a new piece of return hose for your steering pump since they always seem to leak and drizzle all over the place, you'll be right there (fix another common problem). New plugs if you need them ...oil, antifreeze (might as well buy the pre-mix extended life) ...don't use tap water, minerals will eventually clog your radiator (if you used tap water before, flush it and use distilled or filtered. How are your wires? You need extra-good wires on these GEM Discos ...I'm running STI's. What's your lower radiator hose look like? They have that funky junction that connects to your fill tank. Don't neglect the lower radiator hose, they can split at the junction and ruin your motor. A lot of L/R owners go cheap and don't replace that expensive hose and end up with damage, so replace it if you have ANY doubts because you'll be right there with the coolant out anyway. Get a Harbor Freight torque wrench if you need one. All this is going to be kind of pricey, but when it's done you'll have fixed something all these L/R's eventually need done. Park on a steep hill with the nose in the air when you're adding coolant.

 

Mark, I'm blowing through coolant pretty quick but I almost can't tell where.There is nothing leaking under the truck. I do have some visible exhaust but I live in a very wet climate, Portland, OR, and even new Hondas have visible exhaust when warmed up in the morning around here. It's not pluming anymore after I did the intake valley gasket swap. I also am wondering if my thermostat is bad and is causing my mostly distilled water coolant to boil and blow out the expansion tank cap. Does that make any sense?

If i don't top off the coolant each day my temp spikes WAY high for a minute then drops back down to normal. It really freaks me the eff out, I can hear the motor start to sound funny before it drops back down too.

Before and after the intake gasket change I am running 3 codes. Random misfire, Cylinder 5 misfire, and excessive emissions due to misfire. I cleared the codes after the work and they all came back. Does that shed any light on the issue? I replaced the plugs, wires and oil at the time of the gasket too but used regular NGK wires. I have an upper radiator hose ready to replace.

Before this post I had planned to re torque the intake down and swap thermostat. Is 38Nm the correct torque?

Funny you mention a Jeep, I have a 95 Grand Cherokee with 300k but I like the rover more!

 

You might not want to take any family vacations with that truck anytime soon!!

Are you saying you have coolant 'blowing' out of the coolant reservoir? Was it doing that before the intake gasket repair? Are you getting excessive coolant pressure ..so much so that the upper radiator hose looks kind of like a blimp?

Do this:
1) Look into the reservoir with a flashligt and have someone give it a little throttle, not too much. Look for bubbles as the engine speeds up and runs around 1200 - 1500 rpm.
2) At idle, sniff into the reservoir, do you smell any combustion gasses?
3) When you took out your vehicle's spark plugs, did any of them look super clean ...like brand new? If so, that's where your leak is. If you don't remember, try taking them out and looking at one -- start with #5. A leak basically steam-cleans the spark plug.

Computer is deducing an improper O2 profile probably due to coolant in the #5 combustion stream. That, or coolant has fouled or is fouling the plug and it may un-foul too after it runs a little.

How many miles on this truck, How long have you owned it? Have the head gaskets been replaced before as far as you know? Do you think the engine has ever been overheated? Does it use excessive oil?

I wish I'd known the symptoms before doing the intake project. I would have suggested new head gaskets too, unless you think they've been done before.

 

126k Miles, I've had it about 6 months. Friend A used to own it, sold it to Friend B. I bought it from Friend B. Friend A has owned other D1s and did the lift on this one. Friend A knows what he's doing but it looks like Friend B let it fall apart. Friend A helps me work on it all the time. I do not believe the heads were ever pulled. I do believe the engine has been overheated.

Yes I do believe that coolant has blown out of the reservoir. The top hose does not appear ballooned but I am questioning the connection from top hose to thermo housing.

I have my plugs from the changed that are labeled. I'll check after work and run though that procedure you gave me. I can say right now that yes I smell combustion gasses in the reservoir.

 

Well, I would dig into it and take the heads off. This is about the miles where the head gaskets start failing. It's real common. It shouldn't take long now that you know how to get the intake off. Don't order any parts at this point. When you get the heads off, be very careful with the head gaskets so you can closely inspect them. Treat them like a treasure from King Tut's Tomb because they tell a story. Look at the intake, it should have #5 cyl listed ...look at that part of the head gasket around the #5 cylinder first ...between the coolant passages and the cylinder sealing ring (on the head gasket that seals around the actual cylinder). Inspect very carefully with a flashlight. What you're looking for is an area where the gasket has degraded, corroded or split apart, kind of like a couple layers of tag-board might pucker and allow moisture to seep through. It's getting past that ring (hopefully). If you don't see anything, look at the other cylinders on the H/G too. Hopefully you'll spot the problem on the head gasket right away and that would be a good thing.

The reason I say hopefully is there's a chance if the block has been overheated sufficiently there are other deeper problems like a sleeve sealing problem, or worse (cracked block). But 90% of the time it's the headgasket. These L/R blocks can't tolerate much overheating, especially the later 03-04's, ..but ours are much better. If you see a spark plug that looks super clean when you're taking it apart, that's generally where the leak is. Once you get it sorted out, then order your parts and get the heads redone, with a good 3-angle valve job and new stem seals, etc.

 

Mark, you've been a huge help! I appreciate all the info. I'll make phone calls to a local shop that always has L/R and such outside about rebuilding the heads. I'll post up a picture of my #5 plug this evening. I should be able to start this work next week.