That's that done then. Only took three days.

BX Tech talk
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Way2go
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Post by Way2go »

ed4ferrets wrote:
ed4ferrets wrote:Okay, I have a car which is more than twice the age of some of you young whippersnappers out there :wink: It has an original steel vertical core type radiator which I can therefore visually see the clumps of rust etc from above.
I have used a bottle of proprietary type rad flush (10minutes) which did loosen and flush out some gunge but I can still see loads. Would running it on a vinegar mix help with a rusty steel rad without damage :? ?
----^

Surely there are at least 3 wise men who can advise :cry:
IMHO you were too quick to dump the rad flush. I was recommended by an expert to keep the Wynn's professional flush in for 100 miles when I had the red light problem with OK temp guage reading. In actual fact kept it in for 2 days and cycled from cold to hot about 6 times before dumping. (red light was cured after 2 cycles and I suspect head silt was problem).

So long as the rust hasn't eaten substancially through the metal anywhere then a proprietary flush in this way followed by a water flush and backflush should be all that you need. :D

Vinegar in a BX engine with wet liners may not improve its longevity. :cry:
1991 BX19GTi Auto
roscoe
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Post by roscoe »

I've run a rad flush all week in the TZD - am dumping/flushing it tomorrow but haven't noticed any improvement in cooling. Running around town, car only gets up to about 80C max. but on motorway at 120 kmh, it runs at 90C and when going uphill, gets up to 100C and that's with the thermostat out - took it out a few weeks back. Going downhill, cools back to 80C, so I'm thinking it has to be the radiator flow being restricted. I'm planning on pulling the rad out tomorrow and using a mix of hydrochoric acid and demineralized water in it - let it sit for a few hours and then flush out. Will this work and what % of acid mix is recommended? While the rad is out, I'll flush the cooling system with the garden hose - backwards from the top so is against normal water flow direction.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
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Post by Way2go »

roscoe wrote:Running around town, car only gets up to about 80C max. but on motorway at 120 kmh, it runs at 90C and when going uphill, gets up to 100C and that's with the thermostat out - took it out a few weeks back. Going downhill, cools back to 80C, so I'm thinking it has to be the radiator
If you only heat to 80 around town then cooling system sounds fine as with the thermostat in the guage should read about 90.

First of all check when up to temperature that the radiator gets hot in the vicinity of the fan switch low down on the radiator.

If it rises to 100 under load then falls back to 80 off-load then it is probable that the fans are not cutting in. Check fans by grounding the switch contacts to see if the fans run. If they do then maybe this switch is defective.
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jeremy
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Post by jeremy »

Diesel theremostats open at about 82 degrees.

Many engines won't cool properly without a thermostat in place as the water won't circulate correctly - I don't know if this affects Citroen engines but if the thermostat is working correctly I cannot see any possible advantage in running without one.
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Post by Way2go »

jeremy wrote:Diesel theremostats open at about 82 degrees.

Many engines won't cool properly without a thermostat in place as the water won't circulate correctly - I don't know if this affects Citroen engines but if the thermostat is working correctly I cannot see any possible advantage in running without one.
I agree Jeremy & originally incorporated this point in my reply above before editing it for brevity. The radiator and engine can get as hot as it likes or dislikes at the top BUT if it doesn't get hot at the bottom of the rad then the fans wont cut in and cool it down.
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Post by roscoe »

I don't see what difference the fans would make on the highway at 120 kmh - the air coming in the rad at that speed is far more than the fans would produce - and that is where the car is running hot - not around town. I've checked my fans and switch and they are working properly - so I've ruled that out. I will put the thermostat back in today but am going to pull the rad and fill it with a weak hydrochloric acid solution to see if that will help things - my suspicion is that it is partially blocked. The rad is getting hot down the side where the fan switch is and feels hot all the way from top to bottom - but could still have very restricted tubes in it.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
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Post by jeremy »

You're right - fans won't make any difference over about 20 MPH - so its the rad!
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Post by roscoe »

It's the rad - pulled it out this morning and it's plugged - very little water flow through it from a garden hose on full pressure. So have filled it with the HCL solution and will let it soak for a few hours. Reinstalled thermostat, tested fan switch with heat - works OK, so once the rad is (hopefully) a bit cleaner, will reinstall and test. If not, then I'm going to have to bite the bullet and get one from GSF... :cry: :cry:
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
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Post by Way2go »

roscoe wrote:It's the rad - pulled it out this morning and it's plugged - very little water flow through it from a garden hose on full pressure. So have filled it with the HCL solution and will let it soak for a few hours. Reinstalled thermostat, tested fan switch with heat - works OK, so once the rad is (hopefully) a bit cleaner, will reinstall and test. If not, then I'm going to have to bite the bullet and get one from GSF... :cry: :cry:
Glad you found it! Interesting it didn't overheat around town as my petrols when in trouble have exhibited this only at slow speeds.
Do diesels run cooler than petrol at idle/slow revs then? :?
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roscoe
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Post by roscoe »

Don't know if the diesels run cooler at low speeds/rpms than the petrols, but they have bigger radiators. My 16V used to run around the 95-100C in town and sometimes hotter if traffic was heavy and was moving very slowly, whereas the TZD doesn't get above 80C in town, no matter whether it's moving or not. Were the opposite on the highway though, 16V cooled down to about 85C, TZD gets up to 90C - but that should be solved with the rad cleanout.

FYI, I left the HCL solution in for the best part of the day as I had to go and see some friends, came back tonight and gave it a good flushing out with the hose. Looking inside now with a light - shiny and clean and the cores look clean as far as I can see as well. Water flows through it a lot better than it did this morning! Got it all back together tonight, but didn't have enough coolant to finish filling it up, so will do that tomorrow when the autoparts store opens. After I get it bled and filled properly, will take it out for a good run and see what happens - will let the forum know.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
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Oscar
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Post by Oscar »

I'll tell my mate John that his HCl tip has gone as far as Oz. He'll be pleased.

O
(Red BX 1.7TZD ("Well, it is a style icon" - Tom Sheppard)) "Was", Tom, "was"
roscoe
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Post by roscoe »

Results of road test this morning:
Bled system, ran up in garage till thermostat opened (85C) or so on gauge, temp stayed at that level no matter how long I ran the engine. Took it out on the road, first around town for about 30 minutes - temp sat right on 85C, never moved. Then headed up the hill to the freeway - going up the hill in 4th at 2500 rpm - temp went up to 100C and stayed there until I got to flat road at top then dropped to 90C as I shifted up and speed increased/revs decreased. Got only freeway - temp went up to 105C (I then turned the interior heater on full to help cool engine), stayed there until I got to a nice long flat stretch and at 2800 rpm/110 kmh temp sat on 90C and didn't come down until I came off freeway and back into city driving - then dropped to 85C again. So although the rad looks clean from the ends, it must still be partially blocked internally.
Which means I have two choices - try the HCL treatment again (and maybe a few times to try and really shift the blockages) or get a new rad. I'm worried that too many hits with acid will eat through the core somewhere and I'll be stuffed anyway, so think a new rad is probably the answer.
The fans are cutting in on both low and high speeds, and the thermostat is back in the engine - which is probably one reason it is running a bit hotter now than before - more restriction in the water flow with the stat in.
My bottom rad hose is soft but doesn't feel soft enough to be collapsing under suction - but I will change it out when I do the rad as well. Figure I might pick up two cheap flexible hoses from local cheapy auto supply shop - the ones with an internal wire coil to reinforce them, cut the hoses open, remove the wire coils and wind them into the lower rad hose - that way it can't collapse at all.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
roscoe
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Post by roscoe »

Latest update - car is on ramps - rad is stuffed :x :x Took it to local rad shop to see if they could clean the core out - the end alloy header cracked open when they tried to unclip the plastic end tanks - so it is definitely a new rad job! They did make me up a lower hose - very nice job using two different sized reinforced rubber ones on the ends with a metal section in between to match the existing shape.
I've emailed both GSF and Lockwoods to get prices/shipping details but no response so far - guess they aren't as desperate as I am!
My previous order from GSF got caught in customs - over the AUD$250 limit so I'm waiting to get the bill on that one as well (drop links, rear arm bearing kits, front strut return hoses)...has not been a good week :cry:
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
roscoe
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Post by roscoe »

New rad arrived today along with a new bottom hose from New Zealand - got both of them in tonight and filled/bled it with new coolant. Took the car out on a nice long run up the freeway on the hill it used to get hot on - temp gauge never budged off 82C or so - even when flooring it from the bottom up - so new rad has definitely done the job :D :D . Now I've just got a n/s outer CV boot to replace - noticed it as I was under the car :x - and I thought I might have one weekend 'tool free'..
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter
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