landrovermanuk Posted March 17, 2013 Share Posted March 17, 2013 I've been having problems with the 3.9efi in my 90. For months it has been running rough, stalling, spluttering etc. I've replaced the coil, dizzy, cap and rotor arm, spent money at the local L/R garage, still no improvement. I decided to start at the beginning and change the fuel filter which isn't that old. So go to change the filter and find a big split in the fuel pipe. So replace the pipe and it starts running a lot better. I take it out for a test drive but it's running quite right. Under acceleration it's not got full power. It feels like it's running on 7 not 8. I get home pop the bonnet and notice that there doesn't feel like there's any water in the top hose. I then notice that a short hose from the inlet manifold to the metal pipe that leads to the heater has swollen in the middle and the hose clips are all cruddy. I open the expansion bottle, it's got water in, so has the rad and when I take the short hose off the engine has water in. So it looks like it's just the top hose and heater hoses has no water in... So I'm replacing any old looking hoses and clips.... But does it sound like a head gasket? Rough running and water loss or just a small leak and air lock? I think the engine has less than 80K on it... Thanks for any tips or advice.... All the best John... Quote Link to comment Share on other sites More sharing options...
discomark10 Posted March 17, 2013 Share Posted March 17, 2013 might be an air lock, ide check the thermostat also, if that works could be the pump. also the fuel pumps can be a bit temperamental and cause bad running. could be a faulty regulator. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 17, 2013 Share Posted March 17, 2013 Could be an airlock / stuck stat, that's a cheaper thing to do than a head gasket... start with the cheap & easy stuff! Fit a genuine stat with the bleed hole upwards. Quote Link to comment Share on other sites More sharing options...
landrovermanuk Posted March 17, 2013 Author Share Posted March 17, 2013 Thanks, I'll give the thermostat a try. As there wasn't loads of steam coming out of the exhaust I was working on the theory that the head gaskets were ok(no water in the oil or oil in the water that I could see). I think it could well be an air lock as I've looked at the inside of the metal pipe I've taken off and there is a little rust in it. Late summer last year I put a new heater in, plus a/freeze and the heater worked really well so didn't think I had an air lock but it's looking likely. So I'll be investing in some water pipe, hose clips and a thermostat in the morning... I must admit I was rather pi55ed thinking I'd cured all my problems to find it still running rough... I'll sort the water problem first then maybe just take it to my L/R man.... I'm starting to get fed up with L/Rs already this year and I've got a Series 3 that needs a ground up rebuild....lol Thanks for the help the earlier post was written in a rush so didn't know if it made sense... John Quote Link to comment Share on other sites More sharing options...
Quagmire Posted March 17, 2013 Share Posted March 17, 2013 I wouldn't worry too much about how much water vapour a v8 produces, I have to back out of my space in the mornings- a distance of 40ft or so and sometimes its hard to see anything in the passenger mirror due to the amount of vapour being generated! Quote Link to comment Share on other sites More sharing options...
landrovermanuk Posted March 20, 2013 Author Share Posted March 20, 2013 Thermostat is in. Now I do have an air lock...lol I've cleaned all the plugs, which were very fouled That was caused by the rough running. When I warmed it up to try and get the air lock out it ran well. So once I've got it cleared I'll try a test run...Look's like I know what I'm doing tomorrow... Thanks for the advice.... John Quote Link to comment Share on other sites More sharing options...
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