Another 4.6 with top hose pressurising liner symptoms

[gulf blue rsr]

Hi, I've been away from v8's for a while but got the bug again and took a gamble on a p38 Range Rover with a 4.6 in it on Thor 1999 reg.

When I bought it I had suspicions that it may have problems and that it may have already had some "instant block in a bottle repair" but it was cheap enough to stand me having to put an engine in it so I took the chance. There are signs of water overflow stains to the header tank and around the top hose on the rad and engine more stains, the guy I bought it from admitted that he had changed one head due to the exhaust manifold blowing and damaging the flange face, I took this with a pinch of salt!! when I questioned if it had any water issues he was very positive that it was not and never did use any water, again more salt!! He also assured me that he had not put any instant block repair in it...... more salt!!!

So I watched the temp gauge for the last 1500 miles, it runs mostly just above the blue section at about a 1/4 at worst when sitting in traffic or towing (nothing to heavy only about 1.5 ton so far) it will go to 1/2 up the gauge but never over. It has used perhaps about 1/2 pint of water at the most and I keep checking the top hose and no sign of excessive pressure.......

Then all of a sudden I'm sitting in it a couple of days ago and see wisps of steam coming from the bonnet after I switch off, open the bonnet to find top hose hard and a neat little jet of water coming from the waterpump end of it

I have kept using it mostly short trips of around 5 miles even towing the trailer again with only about 1.5 ton but up a couple of pretty steep hills, still the gauge does not go above 1/2 in about 150 miles it has used perhaps a pint of water from the hose when under pressure.

Since I have had it if you try and drive it hard it goes well but as the revs go up it will die down and feel like it is holding back....bit strange and hard to describe, it also has a bit of a missfire, if you are gentle with the throttle it goes fine and does not have the same problem....helps with the fuel bill though!!!

I have one of those sniff test bottles so did the test and says no problem, I have not checked other hoses or anything yet as I just seem to think cracked block so not worth messing with just get it out and top hats fitted, time is my problem with that job at the moment so I'm thinking bring on the irotite but how much time will that buy me is it really worth the money??

Any ideas to try before spending the big money??

Sorry for long post but guess you need all the info!

Steve

[katanaman]

If you have done the sniffer test and it comes up ok then why dont you believe it? They are usually accurate so I would be looking for problems elsewhere to be honest.

[gulf blue rsr]

If you have done the sniffer test and it comes up ok then why dont you believe it? They are usually accurate so I would be looking for problems elsewhere to be honest.

Only reason I guess I'm not convinced by the sniffer test is that I've never seen it actually fail an engine, but this afternoon was talking to a mate of mine and he says that he has used one and seen it fail an engine so I guess perhaps they do work??

I've got a used but known good thermostat so I will swap that over and see what happens, I'll also try and flush the whole system out while it is drained just to see if that helps, and after that??? anyone got any ideas? air lock or blocked rad, if I end up changing the engine I will get a new water pump rad and hoses so I guess I may just change them 1st in case it cures the prob without changing the engine.....

Steve

[katanaman]

yes they definitely work, course you get different makes and different prices so there might be some bad ones out there. Like you say you need new hoses anyway as they sound stuffed, new stat maybe and give it all a good flush. Check the radiator for fin damage and also back flush it as it might well be silted up.

[tobbjo]

Since I have had it if you try and drive it hard it goes well but as the revs go up it will die down and feel like it is holding back....bit strange and hard to describe, it also has a bit of a missfire, if you are gentle with the throttle it goes fine and does not have the same problem....helps with the fuel bill though!!!

Steve

That sounds exactly like the symptom of wifey's Rangie. Also a 1999-2000 Thor. I changed plugs, ignition wires and air mass meter. Just the meter internals, not the tube.
I had a friend drive it while I looked at the output from our Faultmate MSV and my diagnosis was that the hesitation coincided with the switchover from closed to open loop, which led me to the air mass meter.

It fixed the probem and it revvs beautifully!

HTH
Tobias

[gulf blue rsr]

That sounds exactly like the symptom of wifey's Rangie. Also a 1999-2000 Thor. I changed plugs, ignition wires and air mass meter. Just the meter internals, not the tube.
I had a friend drive it while I looked at the output from our Faultmate MSV and my diagnosis was that the hesitation coincided with the switchover from closed to open loop, which led me to the air mass meter.

It fixed the probem and it revvs beautifully!

HTH
Tobias[/quote]

I had wondered about the air mass meter as I know they give problems and see lots of people suggest changing them, I've seen new pattern ones on Ebay which are quite cheap but have shy-ed away from them as you get what you pay for and decided there is no point putting a cheap copy on as if it does not cure the problem I may then be suspecting the copy meter!! Unless anyone has experience with them and confirms they are ok??
I see you say you just changed the internals, can you buy just the internals as a kit or are you just clever with electronics? I ask as my father is a retired TV engineer so if it is just a straight forward electronics job for a few cheap electronic bits then I may twist his arm to get the soldering iron out of retirement!!

Still not had a chance to drain the water out and inspect yet toooo much work to do!!
Thanks for the help

Steve

[tobbjo]

I see you say you just changed the internals, can you buy just the internals as a kit or are you just clever with electronics? I ask as my father is a retired TV engineer so if it is just a straight forward electronics job for a few cheap electronic bits then I may twist his arm to get the soldering iron out of retirement!!

Steve

I bought this one:

http://www.famousfour.com/new_parts/par ... rtID=12518
£59 instead of £99 for the complete tube.

Sits in the tube by two screws. No electrickery fidgeting for me!

T

[gulf blue rsr]

I bought this one:

http://www.famousfour.com/new_parts/par ... rtID=12518
£59 instead of £99 for the complete tube.

Sits in the tube by two screws. No electrickery fidgeting for me!

T[/quote]

I see, looks like that will be my next step then, Thanks Tobias

Hoping I've had some good luck tonight, managed to find time to drain and flush the system, all the water looked very clean with no sign of any rust or muck in there, decided that being as I had a known good second hand thermostat that it would be worth the effort to fight with all the spring type hose clips and get the thing out from all the hoses.

Glad I did, looked inside the stat when I got it off to find the valve had come unseated from its spring retainer so was constantly open just a small amount so always a slight flow of water but I guess that as it was not properly seated I doubt that it would then work and fully open allowing full flow hence the pressurising..... I hope!!
My only concern now is that the previous owner may have been having pressurising problems so tried to bodge the stat open so it would take longer to warm up.

After refilling the system I took it for a hard 40 mile drive up lots of hills...... advantage of living in Wales!! The temp gauge went up to halfway and stayed there all the time! Since I've had the car it has always jumped up and down 1/4 and 1/2 with no real pattern which always seemed wrong. Just gonna run it and keep my eye on it for a week hopefully I have a happy cheap end to my problem

Thanks for all the help and advice with this one
Steve

[tobbjo]

That's the way the temp gauge should behave/behaves in wifeys rangie.
Glad you could (hopefully) fix it.

Did the hesitation/strange running disappear too?

T

[gulf blue rsr]

Fingers are very crossed that yes it is hopefully fixed!!

No running issue's still there was thinking that just maybe the fact that it was not getting to temp properly that perhaps it would improve now but no such luck! Not complaining should be able to sort a misfire and stutter cheaper than an engine rebuild which was what I was looking at 24hrs ago!!

Been reading up on the afm's and opinion seems to be to unplug it while it is running, keep it revving and it should keep running and then take for a test drive, if the problem clears then it is the afm....... will try this today and report back!!

Steve

[tobbjo]

How about the spark plugs. They are expensive, so many hesitate to change them. Ours were so run down they looked like the ones I took out of a boat engine from 1972!
Rusty and worn.
It might be that the new plugs made a bigger difference than the AFM.

T

[gulf blue rsr]

looks like I've still got water problems used the car for the past week, probably about 150 miles or so, temp gauge stays steady at halfway up just like it should, not using any big quantity of water and the all of a sudden gauge flies up to the max and boils the water left it to cool for an hour and it took 3/4 of watering can to fill it!!

Used it for a few days again and not had a over heat prob again even on longer drives though it is definately pressurizing, not even used any water since!

I'm going to pull the water pump out tomorrow and see if I can find anything wrong........wish me luck!!