300 TDI overheating ??

[Reef Inmate]

Hi there.

I recently fitted a brand new cylinder head to my 300 TDI and while the head was off I had the radiator checked out. The vehicle runs fine now. I can drive around town all day and the temp gauge doesn't move. As soon as i go out on the freeway and cruise at 100/110 km h the temp goes up towards the red on the gauge on up hills and then comes down on the flat or downhill sections. It generally runs hotter (above halfway on the gauge) when cruising on the freeway. In and around town it runs on 1/3 on the gauge.
Is this normal and if not what would cause this. The engine is not using water.
Could it be the thermostat or maybe the engine is due for overhaul - its sitting on 330000 km now but I don't know if its been overhauled before.

Any advice greatly appreciated.

PS if it need OH can anyone recommend a reliable outfit in Durban that could do this for me.


Thanks

Leigh

[Rain Hard]

Ja just take it to Paul at "The Centre" 031-3378521.

[wiel]

I think you must change the thermostat.

[rattle&hum]

My 59 Defender runs at 2/3 to 3/4 all the time. Never drops below 2/3 and never above 3/4.

[Cobus Gouws]

Hi

What you describe is clearly your cooling system not doing it's work popperly. When you drive faster the cooling system can't cope with the additional generated combustion heat. Things to check:

1) Does the cooling system seal propperly (expansion bottle cracked?, cap OK?, loosing coolant somewhere else?, etc)
2) Are there any blockages or restrictions in the cooling system (blocked or partially blocked radiator core?, thermostat not opening?
3) Viscous fan OK?


Good luck.

[pretdave]

Hi RI
You say you had the radiator checked out? Who checked and was anything done to it ?
If the rad still has its original core I would not hesitste to have it recored and thermostat and pressure cap replaced.
I would also seriosly consider doing a "tropical mod " on the radiator. The Tropical mod is a story on its own - I will elaborate if nrequested.

Dont delay
The engine is going to bite you soon.
Cheers Dave

[jester]

Hi

Leigh - I would have the radiator and everything cooling system related checked out soonest, a blown engine will be costly - ask me I've gone down that road!

Dave, I've been following this thread and am interested in what you refer to as the "tropical mod", I drive a Disco 1 Tdi, please give us some info re this, thanks, Craig

[Reef Inmate]

Thanks for all the replies.

When I did the head I sent the radiator to Silverton in Durban and they said it checked out fine. I asked them to clean it and pressure check it.
I think the viscous coupling may be at fault. When I got home from work today and switched the car off I could turn the fan. If I am correct I shouldn't be able to turn the fan and it turns easily. There are no coolant leaks and the water bottle is not cracked either.

Regards

Leigh

[pretdave]

Leigh , it sounds like you might have found the problem with the Viscous drive... You can try to fix the drive temporarily with cable ties , to see whether the overheating goes.

Jester , the "Tropical Mod" term , I think , originated in the UK . You will be able to see references on LR4x4.com , landroveraddict.com and landyonline.co.za.

Most of the 300 Tdi radiators have a large internal hole (bigger in diameter than a R5 coin) that allows hot coolant flowing in to the radiator to bypass the core and flow out again without being cooled. Yes , I kid you not!.
This hole can be observed by removing the top radiator plug (originally plastic - if yours hasnt been changed out for brass yet - dont delay - the plastic will cost you an engine soon ) This plug is where the hot coolant flows in . A piece of wire inserted here will be able to move right through to the bottom of the radiator, via land Rovers special hole. This hole is clearly seen on an empty radiator if a light is shone into the outlet at the bottom of the radiator and it is observed from the top. On a brand new radiator , this apparently is acceptable , but as the internal waterways buildup with time an ever increasing proportion of coolant will simply by pass the radiator.

Land Rover has done this with no other radiators , and I am not aware of any other makes that have it. I can only conclude that this was onev of their less successful innovations.

The Tropical Mod consists of getting a radiator specialist to block this hole .
Those who have done it claim an immediate improvement in cooling.
My 300Tdi rad will be recored soon , and I intend having the mod done.

Cheers Dave

[Reef Inmate]

Hi Dave

Have you had the radiator re cored yet? When they fit a new core does it also have the hole through the center?

Leigh

[pretdave]

Hi Dave

Have you had the radiator re cored yet? When they fit a new core does it also have the hole through the center?

Leigh

Hi Leigh
No havent had mine done yet. When I asked for a quote from Silverton , I asked about the by pass hole - as I understand it , the by pass would still be there after a re-core, unless I asked for it to be blocked.

Dave

[TheSaint]

Hi All,

Well I'm very new to the forum.. I actually joined because of this post.
I have exactly the same symptoms which Leigh is describing, in my Auto '93 200TDi Disco.
I find this an unusual fault, because usually engines overheat when at their least efficient ie. in traffic or when working hard at low speeds. My car also can sit in traffic for hours or drive round backroads without a problem. Under these conditions, the temp gauge stabilises at just under 1/4.
But get on a freeway at a constant +80km/h... and she gets warm... and then HOT on the hills. When I first got her in December, I went on holiday up Town Hill 4-up towing a trailer. By halfway up, we had to pull over because the temperature gauge was over 3/4.
I took it in and they replaced the radiator. It improved a LOT, but still has the problem. I can now drive up Town Hill with a trailer, but have to switch off the aircon and at the top it's still heading towards 3/4 on the temperature gauge.
This is not right and as Dave says, this engine is going to bite me soon.

The head was done six months ago, the water pump replaced at the same time. I've replaced the radiator, and the viscous fan is bolted together so the viscous coupling is overidden and the fan is full speed.

Please... anyone ? Help ? I don't want to kill my engine.
Leigh, have you tried any of the suggestions that you've received on this thread ?
I've even considered trying to cut holes in the bonnet and put bonnet scoops to try and get more airflow in the engine compartment.

I'd appreciate any feedback.

Cheers
Charles

[JohnBH]

Hi Charles

I bought my 98 Disco 300Tdi in Nov. The previous owner had a history of Overheating Problems, similar to those discribed in this thread. When I got the car it had 2 huge Cibie Super Oscar driving lights mounted on the Winchbar...right in front of the radiator. After removing these I've had no further problems........the gauge doesn't move off the middle up or down hill..........have you got something obstructing the airflow ?

Cheers, JohnBH.

[TheSaint]

It's got a pair of bigass spotlights front and centre... oh man, who'd have thought ?
They come off tomorrow.
So, how do you put spotlights onto these things if the airflow is so finicky ?

Thanks so much for the help.

Charles

[JohnBH]

I've remounted them on the Roof Carrier, which will only be used on trips. I'm perfectly happy with the standard lights around town. My fuel consumption on the open rd with the roof carrier (Empty) at a steady 100kph is 10.5 l/100km. Without the carrier it's 9.5 so I only use it when I have baggage/equipment I can't put inside.

On the issue of airflow, any obstruction ahead of the radiator will create some disturbance in the airflow. The car was designed with fins in the grill to channel air directly into the radiator/intercooler etc. Even a bullbar will deflect airflow.....look at what they do with the F1 cars. I'm busy trying to design a Nudge Bar that will have minimal impact on airflow, but have not arrived at an optimim design as yet.

There was an article last year about the problems Toyota were having with airflow into the duct on the bonnet of the Diesel Hilux as a result of fitting of aftermarket plastic bonnet protectors which altered the leading edge of the bonnet enough to deflect airflow over the duct in the bonnet....makes you think about the effectiveness of all the add on bits doesn't it ?

I'm also in Gillitts, just above the St Helier Dam in Forbes Dr, we should get together sometime and compare notes.

Best Regards JohnBH.

[TheSaint]

Hi John,

Thanks so much the help. Just read this as I finished removing the spots... now I'm wondering about the bullbar.
I'll give it a try as it is... if it's improved but still worries me out comes the bullbar.
I'm in Ashley Drive up on the other side of the hill. I'd definitely be keen on meeting someone to chew the fat with on this thing. I bought this vehicle as a second car and for camping which we do a lot of. Now I cna also do Mozambique and some of the other Northern neighbours. I've got a roofrack fitted and I get about 10l/100km. In fact on the one trip to the berg(reeeaaally slow because I was stressing about the overheating) but with a trailer and 4-up I clocked exactly 9.64L/100km.
Not bad for a 2-ton vehicle I say, and enough to make the V8-ers cry...

[JohnBH]

Hi Saint

I'd give it a try with the Bullbar, pse keep me updated on the progress. Drop me message on [email protected] and we'll arrange a chat.

Cheers John.

[Fontuin]

Hi John,

I'll give it a try as it is... if it's improved but still worries me out comes the bullbar.

I've owned 4 Defenders and had bull bars fitted to all 4. Some time ago I had to remove the bullbar off my current vehicle and realized how heavy it was so I left it off and will probably never use a bullbar again.

I drive through he bush quite often and drive over small trees and bushes occasionally when I can't avoid it and the standard bumper offers me enough protection, I have never missed the bullbar and my vehicle has no damage to the front, I even hit a large warthog the other day with no damage. I also do not need to fit heavier duty springs to the front to accommodate the weight.

I have only driven with no bullbar for about 6 months now so I might change my mind but I am of the opinion that a bull bar is expensive, heavy, it affects air flow to the engine and it is unnecessary.

[O.B.]

On the other hand, I had an incident where the driver of an A-class mkI merc did a very interesting manouvre in a parking lot. Reversed absolutely full tilt without looking, right into my front. I had no damage, not even paint on the bullbar, while the A class, well different story.

Other time, I did a short but (very) steep muddy downhill, started sliding. At the bottom, the right front hit the wall of a ditch with considerable force. Point of impact at the indicator lens. Mine is designed with a bend around on the side, about 300mm. Bullbar slightly bent, but if that front part of the fender got the impact, damage would have been way more.

Countless other little incidents...

Heavy and cumbersome it might be, I would not leave it at home. I am too accident prone for that

[TheSaint]

I'll give the bullbar a try next, but I'm still fighting with the overheating.
Spots off, I drove up Fields Hill today at 12:00pm. It was about 30 degrees outside.
I had the aircon on to give it a decent test.
Temperature downhill and flat varies from about 1/8 to just under 1/4 on the gauge. Going up Fields Hill .... got to 1/3 on the gauge. that's 1-up inside and no trailer.

Frustrating, I tell you.

The bullbar is designed so that the bars fall only in front of the vertical struts on the front grill. But I'll pull it off and try.
I have noticed that the aircon radiator sits right up against the main radiator. They are almost one. There are fans on the aircon rad, which switch off when the aircon is off.
I'm thinking what if I space them out and try to get some airflow between the two radiators ? Surely this is not normal though...
It's annoying because I want to start playing and putting gadgets on the vehicle, but I fell to guilty playing around when the engine has a problem.