Thread: 300TDI - blown head gasket or radiator?

Many years ago I had a 79 RRC.
Up til this one drive(up to Ayers Rock) I owned the car for about 4-5yrs, pretty much knew all of it's faults.
Many hundreds of thousands of klms were driven in that time too(with a whole lot more to come after that too!
On this one drive to Ayers Rock, it drive up there nicely, but suddenly began overheating.(using the original temp gauge as my guide).
Temp needle sitting at the start of the red zone.
Being that I knew many of the cars probable faults, I had a spare (lower temp) thermostat in my spares box with me.
Easy fix .. change thermo move along.
Wasn't so simple. Engine still running in the red zone, and I still had about 2500klms to get home in the next day and a half.
Next servo I got too, I sprayed the radiator 'clean' with the hose .. etc. etc.
No luck.
With all those klms to do as quickly as I coould, I had to takle the problem another way. Bonnet half up, wedged to allow some cool air into the engine bay ...
At least it got me home at about 90-ish k/h.
Spent the next few months checking just about everything cooling related, and two(trusted) mechanics finally recommended that it's most likely a weird fault with the temp gauge.
It was going to be one of those things I was going to get too one day, but having had everything checked and or changed, and doing so myself too .. I just never got around to sourcing a new temp gauge.
After two years(running in this so called red zone), I was doing something else and accidentally rubbed my arm against the rad .. which proceeded to turn to dust!
Radiator was pulled out and flushed earlier in the process with the overheating, but always came up good, and felt solid.
This one day a few years later tho .. it turned to dust.
Found a reasonably cheap rad for about $300(and back in the 90's Rover parts were horrendously expensive! compared to what they are now)
Fitted radiator and of course the temp gauge settled back to it's regular half way point too!
If your rad is even a little bit 'old' .. seriously I'd say just change it.

My (current)Tdi runs fairly cool(about 82-83), may hit 85-ish on an steeper 80-90k/h uphill climb after a few mins, but settles back fine at the top.
A few days back we had 38-39 degree days and I went for a cruise, air con on and up a less steep hill, it topped at 94.
I don't really have any cooling issues, but I'm still trying to find a better new rad to replace the oldish looking one in the car.

After my experience with the RRC and a few other bombs in that time between then and now .. I don't trust old radiators, even if they look new!

If you do the headgasket, you're probably going to either be requested to do the radiator by a workshop(as part of the warranty) procedure, or you should really do it anyhow if you do the HG yourselves.
So why not just do the rad as a preventative measure anyhow now.
See how it goes for 'ya before you commit to a HG.

Thanks for the advice! I just called TRS for a quote and they said $290 for clean and tested radiator, or around $700 brand new! I thought I heard him wrong, that is way more than I expected! Should I keep looking, or do you think the $290 clean and tested will be okay?

I am slowly learning that the majority of parts in my car are still the originals. So I wouldn't be surprised if the radiator is ancient too. Pretty sure I haven't had it done since I got the disco 4 years ago!

Originally Posted by Binca

..... Pretty sure I haven't had it done since I got the disco 4 years ago!

I only got my 300TDi mid last year, I have no idea on it's history either over the previous 5 years. Up to 2010 it seems to have a regular service record too. (it's weird)

At the moment, my thinking is a $200-ish aluminium rad off ebay is going to be better(for me) than the unknown quantity that's currently in it.

I now put myself in your shoes and think, your option is for a $290 rad clean and inspection .. just to be sure the rad is not at fault.
I have about 5 rads on ebay on my watch list all priced at about $250-ish(give or take $20).
(They come and go all the time, so I watch what happens before I buy.)
So if it were me in your shoes now, I'd take that ebay plunge and try a Chinesey aluminium rad and hopefully it fixes the issue.

ps. how are you measuring the engine temp? is it via a separate temp gauge or the dash gauge?
Many will tell 'ya here that the dash gauge is pretty much useless!
I'll also tell 'ya that it's useless too. I have a separate gauge that gives a digital readout(hence my above temp values of 83 regular, and 94 tops on a hot day with A/C on).
Dash temp gauge didn't move on that hot day with A/C on.
Hopefully you have a separate gauge for temperature. if not, a good investment .. as well as an EGT gauge.

pps. many here will advise against a Chinese radiator, but my experience so far with them has been good(as in they work!!).
So, I have no issues trying something like that myself.

if you ebay '300tdi radiator' there are two Melbourne based sellers with them.
They appear to be one and the same
I recently just got a larger intercooler for my 300tdi from one of them.
(I think their name is performancecool or something similar).
Service is good, quality of this cheapo Chinese intercooler is very high.
I'm in Melb, and I received it in two days in a very large box!

The intercooler is much thicker and I need to mod the housing for the rad and cooler to fit it.
That's another reason I have it in mind to replace my rad too .. even tho I have no overheating issues so to speak.
I'm going to be pulling everything out anyhow and replacing coolant and so forth, so a bit of preventative measure on my part with the rad replacement, as well as having a (seemingly) good spare if anything goes wrong.

When they say " cleaned", are they just flushing it or are they pulling the tank off and rodding it. If you are chasing cooling issues with a tdi and have the radiator out already, then have it rodded. Flushing it would be a waste of time IMHO.

Originally Posted by Binca

Thanks for the advice! I just called TRS for a quote and they said $290 for clean and tested radiator, or around $700 brand new! I thought I heard him wrong, that is way more than I expected! Should I keep looking, or do you think the $290 clean and tested will be okay?

I am slowly learning that the majority of parts in my car are still the originals. So I wouldn't be surprised if the radiator is ancient too. Pretty sure I haven't had it done since I got the disco 4 years ago!

Go to a Radiator specialist and get them to test for engine combustion gasses in the cooling system.
If OK get them to "rod" out your radiator, save some money by removing it yourself and delivering it to them to clean.
To bleed air out of your cooling system, you need to remove the top brass/plastic (if plastic replace with brass plugs) plugs in the thermostat housing and the one in the top of the radiator.
Fill the radiator through this plug hole and when full immediatley replace the plug, then fill the engine through the thermo plug hole, when full replace the plug, the water in the reservoir tank may be overfull, replace the pressure cap and drive until engine reaches operating temp and then park overnight and top up next morning.
Another thing that I do is drill a 1/8" hole through the flange of the thermostat at the 12 o'clock position (as when in place), see how you go Regards Frank.

Thanks everyone! I think when they say cleaned and tested they mean to sell me a second hand functioning one, as opposed to testing mine. Seeing as they refused to test my head gasket I can't imagine they would want to test my radiator either!

Get a new gauge.
Vdo do an electric or mechanical.
Clean the 3 way joiner with the small hoses on it as this bleeds the air.

hi
6 months ago i pulled my radiator (96 disco 300 tdi) gave it to NATRAD...who dismantled/cleaned/tested and gave a clean bill of health for (about) $230 ....I then replaced thermostat, hoses were ok and did a 10,000 km trip to NT and return....all good

my advice is remove rad/get tested and then make decision as to next step. I would not use fleabay rads at all....you might want to go remote someday.
robbo