I don't post much,cause search is my friend,but this one is getting on my nerves! Long story short,I've done the AST elimination,replaced the radiator filler with an 86,blocked the lower hose where overflow used to go,placed overflow hose on 86 cap,replaced the freiking rad cap 4 times already,as well as the t-stat.The car would overheat like there's no tomorrow,and coolant just disappears.Its not coming out of the exhaust(no smoke at all)but somewhere in front,POSSIBLY overflow tank,AND radiator cap.Ive pressure tested the system and have gotten no lost pressure,no coolant in oil,etc.Should I just eliminate overflow tank completely?Im tired of burping the system with the funnel,and adding coolant at every shutdown.Water pump????I have a fluidyne rad,and just a few other mods that shouldn't interfere with cooling,including power FC that hasn't given me a problem before.Thanks for your time

To pressurize the system,I had to kink the overflow hose also.The temps go up and down as I'm driving,more up when I'm at a light,then extremely high losing all coolant.

 

we need to know did this just start since you eliminated the ast? did it work fine with the ast? it takes alot of time to purge the system without the ast in place

 

If you dont see steam in the engine bay and you dont see coolant pouring out the overflow, it is likely a coolant seal failure. I have seen coolant seal failures that didnt cause the car to smoke, however, it wasnt losing so much coolant that it would overheat instantly, you could usually let the car run a couple hours before over heating or low coolant light coming on.

 

the overheat problem started before the ast removal,with the stock rad,I thought the rad was bad so I got the fluidyne,removed ast and has gotten worse.Steam does come out the front,mainly from the cap because of over pressure I think.My IC pipe(at the turbo side)gets wet from coolant but I still can't see in reality where it's coming from.I have purged the system 5-6 times already,and every time after I have to refill.I DO hear and feel coolant on the hoses moving after it's overheated and the car is off,with the cap off as well.Should I block the overflow tank to see if I'm getting air/coolant issue fixed,or should I try a WP instead?Thanks again.

 

This makes me think that your coolant recovery tubing or tank nipple is blocked and coolant can't get to the recovery tank so that it can be drawn back into the engine when it cools. The only reasons steam should come from the cap are 1) bad seal around its outside, or 2) no place for the coolant to go when the cap starts to let coolant out when it reaches the relief pressure.

If it is blocked near the tank, coolant can also escape from the standard joint in the coolant recovery line. That line is not designed to handle much pressure.

 

You did make sure to install a pressure cap on the water filler neck once deleting the AST correct?

 

Good point - I assumed (bad to assume anything...) he did.

Dave

 

Yes I've replaced the cap 4 times already.I've also removed it many times to burp the system,but never went towards the overflow tank.One problem I DID have before,Dave,was water coming OUT I the overflow tank,with the stock rad,and ast.Should I replace the hosing on overflow?

 

My guess is coolant seals and rebuild. I had similiar prob and drove for several years. Finally got a rebuild.

 

I'm trying everything in my power to not accept that great possibility.

I kinked the overflow hose shut,added coolant,burped and drove for about 10-15 miles,stop and go then highway.On stop and go,temps reached 107c max once,then up and down between 97c and 105,then came the highway.I babied it(I usually do),then did about 80-85 for about a mile or two and temps stayed at 97c,dropping down to 91c until I got off exit and drove home where at shut off and ignition on temps went at 105c with fans on.The radiator was not cool but cold to the touch at those temps and fans blowing cold air(naturally).I removed the radiator cap,had what I believed was a bit of air bfore some coolant wanted out,but kept hearing a gurgling noise coming from the turbo area.I could feel the gurgle(almost like a rabbit,ferret water bottle sound when they're drinking water)through the radiator hoses as I felt them.I ended up adding a bit of more coolant and calling it a night.Temperature outside is about 40 degrees if that makes a difference.


(damn that sounded like a novel)
Thanks once again for your input

 

Just to make it absolutely clear, we mean a pressure-relief (0.9 bar) type cap, the same as the AST cap was previously.

Dave

 

Good luck. You may have to do a pressure test to resolve if there is a problem.

Dave

 

As I said above, this IS a pressure-relief cap, right?

Water continually coming out of the O-F tank could be a symptom of several things:
1. leaky pressure-relief cap (not holding at least 0.9 bar)
2. overfilled O-F tank
3. leaky or blocked/kinked tubing, etc., from AST to O-F tank, causing coolant to not be pulled back to engine as coolant cools off
4. crack in the O-F tank itself, below the full coolant level
5. and finally, the dreaded coolant seal problem.

IMO, it would be a good idea to replace the O-F tubing to eliminate that as the source of the problem. It doesn't take much of a leak to allow it to suck air instead of coolant back to the engine. The O-F tubing could also be kinked or blocked, giving similar symptoms. If it is kinked/blocked, you may hear air being sucked in as you open the cap.

Again, good luck with the diagnosis.

Dave

 

Thanks Dave.I'm in the process of getting another O-F tank.I'll keep an update

 

If you want bring the car by the shop and I'll pressure test the system for you.

 

I'll do that Ihor,as long as you don't make fun of my engine area or how it's all a mess!!(and hopefully I can actually make it there without exploding)

 

No poking fun here. Call me at the shop if you like on Monday.

 

Update;

New water pump
New t-stat
Replaced O/F tank and hoses
New cap(pressure release)

Burped the **** out of the system and took itnou for a spin,and max temp on PFC was 102 I believe.My temps before were no higher than 90 after getting on it,now that I don't it jumps up!Parked the car and heard the bubbling,waited to cool and had to add more coolant,and oneni took it out temps went from 87 to 116.The funny thing is that the stock temp gauge will go up and then swings back down to the middle after 20-30 seconds,and that's when I start to see the Temps go back down on the PFC.The fans are also working,and as much as I hate to say it,the ONLY odd thing I found was when burping the system,a piece from the t-stat gasket came up.I checked it(removed t-stat and it mustve been in there from some other time.


Any suggestions?

 

116 is WAAAY too high. Do you have a cooling tray in place?

 

no sir I do not....but without it,would it make temp fluctuate that much?

 

If the coolant seals arent shot, they will be if you let it get up to around 116c a couple more times.

 

sound like its to late

 

ok,let's say the seals are shot,is it worth it opening it JUST to replace the seals?

 

if you don't want to do a rebuild right now, read this.

http://fd3s.net/o-ring_fix.html

 

Depends on the miles on the engine. However, it is pennies difference to replace the major stuff that generally needs replaced. If the engine had less than 10k miles on it wouldnt be horrible to reuse the apex seals, apex seal springs, corner seal springs, side seal springs, etc. However, at the minimum you should replace the Coolant seals, Tension bolt o-rings, dowel pin o-rings, and oil control rings.