I have a 1998 Discovery and in July we had a radiator hose bust. We fixed it and then the radiator reservoir had a crack in the top. So we replaced the reservoir, flushed radiator, replaced thermostat. After we did that it started making a hissing noise. We took it to a mechanic and he said that it sounded like we trash in the throttle and we needed to run a bottle of sea foam through a tank of gas. Well that did not work as the noise got louder (especially when we accelerated). So we took it back. And he then said it was a cracked exhaust manifold and take it to get welded. Well took the land rover to the muffler shop and they said that it was not a cracked manifold and was a blown head gasket. So I took to a third mechanic and he flat out told me he wasn't sure what it was and just to start taking the engine apart and go from there.. (not sure I want to do this!!!!) but the car does not over heat nor are we leaking water anywhere or have water in the oil. When we start it you can see a spark coming from the throttle/head gasket area and feel some air where the head is together (that makes sense - sorry I am a girl) so I am at a loss and don't know what to do.. The muffler guy told me that it would be my best bet to just sell it and offered me 800.00 righ then. (which I thought was fishy)

But has anyone else experienced this or know/hav suggestions on what it could be or what tO do??? I need help... I am without the vehicle and it is awful! Thanks in advance for any help you can give me - Manicka

 

1. Your descriptions are very good.

2. It sounds like you do have a head gasket leak. But there are also other gaskets nearby, like valley pan (intake gaskets) that can make a shrill sound, and there are exhaust gaskets between the head and the exhaust headers. Vacuum leaks can be found more easily idf a clean oil filter or similar sized can is used to obstruct the big rubber tube that coimes off the air filter toward the engine. It will make vacuum max, and noise will be louder.

3. Does not use coolant = good. Not over heat is good, BUT you are depending on watching the gauge and it is not as accuated as an electronic scanner plugged into the test port.

4. There is a cheap way to find the leak location. If you look in our tech section under sea foam induction cleaning, it details how to unplug a rubber line from the side of the engine plenum, and let this suck in a small quantity of the Sea Foam product. This will make exhaust smoke like mad for about 10 - 15 minutes. Smoke will also come out of exhaust and external head gasket leaks under the hood. Your mechanic can do this.

5. It may well be a head gasket external leak. The mechanic can remove each spark plug and check for color. He can also do a compression test of each cyclinder. (you can do this at home with a tester loaned by auto parts store). Since HG leak is to the outside, it is not burning up any coolant.

6. To fix HG requires about $1500 - $1700 at many shops. DIY is like $300 in parts and $200 in machine shop work. When overheated, the aluminum head warps, which makes the gasket leak. The factory limit for flat vs warp is .002 inch, and your printer paper is about .0038 inch, so it does not take much.

7. If you have an infrared thermomter ($29 at some hardware stores) you can point it at the suspected spots where you feel air coming out. If it is exhaust it will get pretty hot. I have an exhaust leak on mine, and if I point the IR thermometer at it, it reads like 400 fdegrees when truck is first cranked up.

8. IMHO if you have an external HG leak, you will have noise, lower power, less MPG, and that little squirt of hot gases going where it should not be going could eventually errode a nice little groove in both head and block, requiring new engine, or very extensive repairs.

9. See recent post from a member doing a head gasket job. https://landroverforums.com/forum/di...ee-pics-45857/ The pictures how the heads and gaskets removed. The rectangular openings at each end of the head are the water passages, and you can see there is plenty of other surface area not near the water. So a warped head does not always leak water.

 

Thanks! From what you have said (especially #8) is sounds like the head gasket.
But the DIY cost is not too bad... Hopefully it is not that complicated. Most mechanics around here where I live refuse to work on them. They have told me they are to complicated. .

 

2x on the seafoam smoke test. id check the seals on the vac hoses behind the throttlebody, they get lose and whistle, wine and buzz, very common before i jump to headgasket just from feeling air... that massive fan up front does funny things to teh air current around that brick haha. try spraying carb cleaner at the hose connections, if the idle goes up, you nailed it.

as for the seafoam test, you can partially obstruct the muffler too to had more pressure in the exhuast to have a clearer view of where if any smoke is escaping from headgaskets, exhaust gaskets etc.

dont ever sell to a mechanic who offers you money. even if the thing was dead and non recoverable, you can make alot more then $800 just by selling off the parts, body panels, glass, motors, electrics, interior, tires, etc etc.

 

Also, a vac leak sounds like a constant tone, while an exhaust leak near one cylinder will sound more "puff puff puff". And a hairline crack in an exhaust manifold can become quite loud, can be on the underside, hard to see. Exhaust mainfolds are cheaply welded up for repairs.

It is also possible to hold a stick (like a broom handle) against your ear, and press the other end against various spots on the engine, you can actually hear noises you might otherwise not notice due to the fan, etc. And the stick does not care if the motor is hot to the touch.

 

Well my sound sounds like a hit and miss engine so would that be like the puff, puff, puff sound?

 

Yes. So next step - no cost. With truck not running, un-plug a spark plug wire near the air leak. Crank truck. If you unplugged the cylinder with the leak, should be quieter, as you won't have the explosions inside the cylinder happening. Truck will run rough.

Turn off truck, re-hook spark plug wire, try ones adjacent to it. There are only four on each side. I would say if you can make a big difference in the sound with no spark plug, you have found the location. This will likely turn on codes that will make check engine light come on. Auto parts store can scan codes and reset for free.

Now, not to be sexist - you said your were a girl. So are you mechanically inclined, or is some one else going to take this on as a DIY project? It takes a good mechanic 12 - 15 hours on this, plus time at the machine shop. About $300 for the gaskets and bolts (can't re-use the bolts, they are "stretch to fit" and only use once. About $200 to have both heads machined at a cylinder head shop (phone book or ask your auto parts store, like NAPA, where it can be done).

You can search for recent threads started by EricTyrrell, who has documented a rebuild with even more than the HG, with pix and video.

We have ladies on here that DIY, we have ladies who step up and ask the questons because their guy don't need no manual, etc. And a gal who rebuilds muscle cars with her mom. And independent gals that like to keep their mechanics on the straight and narrow path (which should be paved from time to time with homemade brownies, the best business bribe, because they eat all the evidence).

Attached is an exploded diagram of the heads. There is a shop manual set, called the RAVE, that every owner should have on their PC. Anyone attempting a head gasket job will also want it. Free download below in my signature.

In the drawings, look at these on the one for the heads, I included the bottom of the engine, and the tope intake section (which also has to come off if repalcing head gaskets):

11 - valve cover gasket - can leak oil, but does not make noise you suggest

27 - that's the head gasket, one for each side

28 - that is an exhaust manifold to head gasket, could also be your source of leak if you were very, very lucky.

25 - intake manifold gasket called the valley pan gasket - could leak vacuum, but not exhaust.

 

All very good information... And we will try and begin with that. But my husband and brother in law (which are NOT mechanics) have said they were goin to start "tearing" into the motor.... UNTIL someone suggested I find a forum and post a thread an see if maybe someone else had has this issue and see if there are some suggestions besides just "tearing" into the motor as the one mechanic told us. And he (hubby) told me that if the info I found out sounded like it was amateur friendly then they would attempt it. If not, then I would have to find a mechanic because he didn't wont to tear anything up. (maybe a little intimidated since so many people have told us how expensive and complicated they are to work on possibly??) so I hope that gave you a little sense of who we are and that (I) am/was a little concerned with them just "tearing" into my car until I got a little more comforting information... Haha

 

1. You husband is a pretty smart guy, after all, he married you!

2. Your husband can use the RAVE manual and this forum, and do just about anything needed to your vehicle. Mechanics are regular men (and women, too). But if an outside professional is needed, search for an indy one, the dealership is very high priced. Many of us "new" owners of older Rovers could never afford one new, and certainly don't have the funding for extended visits to the dealer. Usually we have several members rebuilding an engine, posting photos, etc. One recent poster was EricTyrrell, who has plenty of pix with his.

 

Some members may be local and offer assistance as well. If you put your location in your profile you may get offers.

I've helped some members by phone as well, explaining the lessons learned, what to expect, how to prepare, etc. If you're interested PM me.

The HG job is messy, will likely take longer and cost more than you expect (as with most endeavors), and you may break other parts along the way. If you stick with it though you'll get through it.