Discussion
Hi All
Looking for some info/ advice. I have found a small leak from rad, cant be much but enough after you have run it around 5 miles, hard to spot exactly where it is coming from but looks like very bottom corner of rad nearside, as greenish/blue in that area and no signs any where else Had a feeling as have had to top up slightly past few times I have run her. Topped up last time with new antifreeze wondering just what would best repair stuff to put in. Radweld, Barrs leaks, there are a lot out there. She did not get higher on temp gauge than around 55 usually sits between 70 and 80. This is a 350i V8 Don't really want to take rad out if I can avoid it.
your thoughts please.
Thanks Deke
Looking for some info/ advice. I have found a small leak from rad, cant be much but enough after you have run it around 5 miles, hard to spot exactly where it is coming from but looks like very bottom corner of rad nearside, as greenish/blue in that area and no signs any where else Had a feeling as have had to top up slightly past few times I have run her. Topped up last time with new antifreeze wondering just what would best repair stuff to put in. Radweld, Barrs leaks, there are a lot out there. She did not get higher on temp gauge than around 55 usually sits between 70 and 80. This is a 350i V8 Don't really want to take rad out if I can avoid it.
your thoughts please.
Thanks Deke
DEKE said:
wondering just what would best repair stuff to put in. Radweld, Barrs leaks, there are a lot out there.
DO NOT DO THIS.They have solid particles that will cling and block various bits of the cooling system, the worst case being that it blocks a coolant passage or the whole radiator. It's a temporary bodge at best. If I go to view a car and see residue from these products in the swirl pot or expansion tank, I run a f
king mile.Get it fixed properly.
Echo what's said above, have been the route of rad weld and the like before with other vehicles and it does block intricate areas I know, had to remove inlet manifold on van with water ways and they were blocked solid. The rads in the wedges always go at the corners because the rad is fixed to the body and not the chassis there is more twist which wrecks the corners, the rad obviously needs to be able to move a little in its angle supports but for my third rad I was offered an uprated/improved version with extra waterways and the top /bottom -most waterways, are infact dummy ones that are not actually connected.
Edited by wooly350i on Monday 25th November 20:13
Agree with comments about RadWeld - Emergencies only. Over time it blocks up the radiator, and also can gum up some of the engine block passages too.
If it's an older brass/copper core type, it can be soldered up by an expert, who will also check radiator is flowing properly. I have done a leaking cap joint myself with a blowlamp, (where it joins the tank) but seams are hard to do with DIY blowlamp and solder...
If it's the later aluminium type, they sometimes leak at the tank ends, because the tanks are held on by a line of crimped tabs. You can try squeezing the tabs with pliers where the leak is - GENTLY, as they can break...
Attaching... My rad has gone twice at the bottom, and looking at it again, I reckon the standard way of just bolting it in doesn't allow for thermal expansion. I've put some plastic spacers on this time, and used nylocs, but only just done up the bolts so rad can move a bit...
If it's an older brass/copper core type, it can be soldered up by an expert, who will also check radiator is flowing properly. I have done a leaking cap joint myself with a blowlamp, (where it joins the tank) but seams are hard to do with DIY blowlamp and solder...
If it's the later aluminium type, they sometimes leak at the tank ends, because the tanks are held on by a line of crimped tabs. You can try squeezing the tabs with pliers where the leak is - GENTLY, as they can break...
Attaching... My rad has gone twice at the bottom, and looking at it again, I reckon the standard way of just bolting it in doesn't allow for thermal expansion. I've put some plastic spacers on this time, and used nylocs, but only just done up the bolts so rad can move a bit...
Edited by RCK974X on Monday 25th November 19:27
All
Thanks for feedback. My dear departed Dad used to be a full time rad repairer many moons ago. As car is 1987 looks like it is older type. Not sure if there are any places up here in Moray North East of Scotland that can do a repair or refurb but will try and find out. As a matter of interest what like a job to remove from car.
Deke
Thanks for feedback. My dear departed Dad used to be a full time rad repairer many moons ago. As car is 1987 looks like it is older type. Not sure if there are any places up here in Moray North East of Scotland that can do a repair or refurb but will try and find out. As a matter of interest what like a job to remove from car.
Deke
Car up on axle stands and remove front balance via its 4 bolts (well mine has 4). Two at front accessed via headlamp pod hole and two down the side through pod access hole.
Disconnect rad and remove from underneath, obviously do all the safety stuff like chock wheels, use decent axle stands,hand brake on,disconnect battery etc etc.
Disconnect rad and remove from underneath, obviously do all the safety stuff like chock wheels, use decent axle stands,hand brake on,disconnect battery etc etc.
DEKE said:
I have found a small leak from rad -------- She did not get higher on temp gauge than around 55 usually sits between 70 and 80 ------- Don't really want to take rad out if I can avoid it. Your thoughts please.
My thoughts - a differing viewpoint.From the above description, I think the thermostat is wide open, hence the low running temperature. Also 70 to 80 is a bit low for a V8 Efi.
Regarding Bars fluid, etc, different opinions abound.
Firstly, a needful flush and reverse flush the whole system using a garden hose at domestic water pressure.
Disconnect the small diameter connection (about 1" dia) adjacent to the water pump and connect the hose to both open ends in turn to flush and reverse flush the system, repeat a couple of times (3 in all).
That will likely shift most of (perhaps) the many years of accumulated crud from the radiator, matrix and engine block water jackets and galleries. Cabin heater should be set to 'hot', methinks!
Need to put in a good 88 deg C thermostat, reconnect the hose connection, then leave the system filled with water, bring the engine up to full temperature and burp out all the air trapped inside the cooling system.
Usually this first burping causes lots of escaping water.
In all probability one can identify the source of the coolant leak or leaks using just water, without losing any expensive antifreeze mixture along the way.
If its a big radiator leak then get it re-cored and fix any other problems too, but if it really is a small leak, then choose a solution. Re-core or seal.
For little leaks, I favour Bars Fluid myself. It solidifies when hot and in contact with air so it's important to eliminate air locks (trapped air).
From the workshop manual documented coolant fluid capacity of the system, work out what ratio of anti-freeze mixture is needed and empty enough of the water, via the rad bottom hose, to replace it with the required amount of antifreeze, then top up with water as one re-burps any trapped air.
This will give the ratio of water to antifreeze desired.
(More burping from scratch is required if one alternatively empties the system and refills with mixed antifreeze.)
Run the engine to thoroughly mix the antifreeze then allow to cool.
Draw off and save enough fluid (say 3-400 ml) from the radiator with a large medical syringe to allow space to pour in the contents of the Bars fluid (or other chosen additive) container.
Re-top-up with the extracted fluid and reseal the rad.
Run the engine again to thoroughly mix the sealing fluid and bring it all up to running temperature again.
Fairly quickly, the fluid gets to work and it's little golden balls seal any small leaks as it solidifies in contact with heat and air.
With a working 88 deg C thermostat and no trapped air the internal coolant pressure should rise to a maximum of about 15 psi (according to what pressure cap is fitted) and the engine temperature should be around 90 - 95 deg C for an Efi V8.
If the leaks have been cured, the cooling system holds pressure.
I should mention that the cooling fan should be working to specification and correctly shrouded.
There may be a bit more burping needed.
If one chooses to follow my suggestions, first mug up on the burping process, some stuff on the most efficient operating temperatures then read all about a typical RV8 cooling system and how to diagnose and resolve fault conditions.
These are all essays I put together for the RV8 as fitted to an Efi SD1. I'm sure that most of it can be applied to a 350i.
Some forum members like to be re-directed to PDF links. If so, read, download and print off any of my stuff from here:
V8 Coolant Fill without Airlocks
http://www.vintagemodelairplane.com/pages/TipsAndT...
What Temperature is Best for Rover V8
http://www.vintagemodelairplane.com/pages/Snippets...
Rover SD1 V8 (Efi) Cooling System - Fault Diagnosis & Resolution
http://www.vintagemodelairplane.com/pages/Rover_Te...
If any stuff needs to be amended for TVR, someone will surely advise.
Radweld is pointless for the radiator as the vibrations soon work it loose. If anything, try stuffing some liquid metal on around the outside (right into the fins etc) which might seal it.
I've lived with a slight weeping for a few years just like you describe (from the radiator too ! ;^)
I would advise you leave it alone until you are spending more than a tenner on antifreeze a month. As to have the radiator recored will cost about £150. Plus it is an arse to get it in and out, budget 3 or 4 hours (or the equivalent in garage fees.)
I've lived with a slight weeping for a few years just like you describe (from the radiator too ! ;^)
I would advise you leave it alone until you are spending more than a tenner on antifreeze a month. As to have the radiator recored will cost about £150. Plus it is an arse to get it in and out, budget 3 or 4 hours (or the equivalent in garage fees.)
Hi Deke, i had similar leak on my 350i.For a quick fix find where the leaks coming from usually bottom right [when standing at front of car] drain down and put Metal two part putty on effective area and leave till solid, there's two locating pins on bottom of rad when fitting back on i put rubber washers on to save the vibration cracking it again, worked on mine and is fine to this day.
I'm with HJ2, bars leaks for small rad leaks works well.
I've never used radweld, but I have seen it used sucessfully after an accident punctured a rad. I believe it cures with heat/air - if your head gasket is fubared then it'll cure in the water passages within the head giving the problems outlined above - but by then you're in a head off/strip down scenario anyway. And blown head gasket symptoms are not the same as a leaking rad...
I've never used radweld, but I have seen it used sucessfully after an accident punctured a rad. I believe it cures with heat/air - if your head gasket is fubared then it'll cure in the water passages within the head giving the problems outlined above - but by then you're in a head off/strip down scenario anyway. And blown head gasket symptoms are not the same as a leaking rad...
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