Coolant leaks out from here
 

Hello
I have a 2001 Boxster S with ~143,000 miles on it.

For the last 2 months (and I have barely been driving this car more than 10-20 miles a week during those months) i have had a serious coolant leak.

Most of the coolant leaks out as soon as the engine starts running from the middle bottom of the car (picture attached). The coolant tank then drops to much below the minimum level.

When I was jacking up the car as well some of the coolant poured out but I think that was just residue from the earlier leaks collecting there.

This problem did not exist in May, but has started since June. At first I thought the issue with low coolant was due to excess heat and evaporation. But that is not the case as now I can see a leak happen as soon as the engine starts.

I don't know what has changed. I have never done anything to the car since May besides getting an alignment at a Firestone while getting new tires installed by them.

I have also never opened up the undercarriage of the car or got work done there. I have done the oil changes myself and the brake pad changes myself.

How do I figure out what the problem with the coolant leak is ? Is it some damage caused during the alignment ? I cannot prove that is what has happened at all, as it is just conjecture on my part.

What is the best way to go about diagnosing the problem.

Please advise.

http://986forum.com/forums/uploads02...1630175255.jpg

I think it may be time to take to consider replacing the water pump.

is water pump failure causing the leak or is the process of fixing the leak an opportunity to also replace the water pump ?

First thing to do is a visual inspection of the suspected area of the leak.
If you find nothing obvious (like a leaking hose).
Then get a coolant system pressure tester.
Places like Harbour freight have them for a reasonable price.
You can test just about any coolant system with them as well as the coolant cap.
With the test kit is it easy to find leaks in coolant systems.

People will say change this or change that. That is Poor way to do things.
Find the cause of the problem then fix the problem.

I went and purchased the Harbor Freight radiator pressure test kit and will try it out.

Agree that I want to find the cause first before trying out solutions.

Thank you.

First thing to do is to STOP driving the car

Next - remove belly pans
Next - Look to see where coolant is coming from

From what I can tell in your picture I am looking at the the area where the aluminum pan (brace) and the plastic under body trays meet.
Remove that plastic under body tray and you should see where a number of coolant hoses meet up.
Then top your coolant system off with distilled water and pressurize the system with your tester. You should have no problem finding your leak..

Once it is repaired then us the tester to again pressurize the system so you can make sure everything is ok.

+1 to blue and Stl's comments. Remove belly pans, pressurize the system, localize the leak. DO NOT DRIVE UNTIL IT'S FIXED.

Sent from my SM-G970U1 using Tapatalk

VK,

I should have mentioned this in my first post.:eek:

Another item that is a common coolant system problem is the plastic coolant fill tank in the rear trunk.
They develop hairline cracks with age.
You should remove the carpet and the sub floor in the trunk.
Strip everything out Down to bare metal.
Then when you pressurize the coolant system you can check the plastic coolant tank as well.
Keep me posted..... if you need to replace the coolant tank I can give you a few pointers.

Thank you all. blue62, I filled up the tank all the way, I did the pressure test on the tank as per the Bentley manual using the harbor freight kit and it did not show any sign of leaks in the tank area. At least the tank is not cracked and was still full after the pressure test.

I flipped up the bleeder valve locking clip a couple of times and there were no leaks and drips initially when I started and moved the car back and forth in my garage to driveway. I drove the car for 0.5 mile locally, and saw no leaks or drips at all. Coolant level looked full in the tank exactly as it looked when I had filled it up

Drove it for 5 miles after waiting 30 min, and making sure there were no drips or leaks.

After the 5 mile drive is when I noticed that the dripping began again in 3 different spots which coincide with hose placements most likely - 2 in the middle of the car and one near the front of the car towards the radiator.

I am waiting for the car to cool down to check the coolant level after the dripping has stopped. Most likely the hoses are failing when the car gets hot.

Then I will redo the pressure test and look for hose leaks again.

I am contemplating that in a hot condition the hoses may be expanding to cause dripping/leaking and when cold the car does not drip. Most likely the hoses have gone bad or the clamps have become loose.

From your description, I doubt the hoses are your problem. That's generally not how hoses go bad. I'd suspect your water pump. More specifically, the shaft seal.

Thank you piper6909.

1) When you say "water pump" is that the same as "coolant pump" in the Bentley manual ?

2) Is the "shaft seal" same as "crankshaft seal" ? that repair work is beyond my capability at the moment.

What would the approximate cost of repair be for this at an independent repair shop ?

Yes to 1, no to 2.

Sorry if I wasn't clear. The coolant pump (water pump, as it's often called) has a seal around the pulley shaft. It is not a replacable item, though. You'd have to replace the entire pump.

I suspect that's where your leak is coming from. If you haven't done so already, remove the belly pans like stl-986 wrote, and take a look aroung the water pump to be sure.

Or you can probably remove the cover behind the seats and look from there, but I believe you'll get a better angle from underneath.

Wait, did I read correctly that it's leaking in the front too?

I have run out of time today, but I will try it this week and get back to you all.

Thank you.

you really just need to get it lifted in the air, remove the pans and the pressurize the system. That is the safest method to finding the leak. Otherwise have it towed to a shop and have them find it and fix it.

If you continue to drive the car you will end up causing more damage and then will be asking what it takes to remove & replace the engine.

With coolant leaks and major oil leaks you dont want to just keep running the car to find the issue, it will be worse for your wallet.

Yes, you could have a host that is failing when hot, but pressurizing the system will show hose issues also, without the engine getting hot & overheating....which WILL happen if you continue to drive it or run the engine.

sort of. there was drips from the front body part area, and then also from the plastic shield cover area. It could just be the same leak flowing forward since my driveway slopes downward and the car nose was along that slope.

I did not take a picture but next time i will take a picture to mark the exact location. Either way I have to lift the car up fully and take out the plastic shields and examine stuff.

VK,
Sounds like it could be the water (coolant) pump.
Once you get it in the air and remove the body under panels you will be able to get eyes on it.
The coolant at the front could be from coolant running along a hose or on the body under panels.

I have looked at your blog.
I see your not afraid of something like this.
you will be able to do this repair no problem.
You just need to get "eyes on" the leak so you know if it is hoses or water pump.
Once you identify the problem you will have no issues.

Leak from the front kind of changes direction to some degree. It very well could be either of the radiators or the center one since you have an S.

Your right though, getting the covers off and eyes on it will help.

One thing you could do to help, get the covers off, then lay cardboard out under the entire car. pressurize the system. The cardboard will act as an extra set of eyes and help you pinpoint the location.

Getting it on level ground though will be necessary obviously

In that case, yes, it could very well be rolling toward the front of the car with the driveway slope. Otherwise, although highly unlikely, it could be one of the tubes running to the front of the car.

I had this weekend a small leak pretty much in same location as the OP has, showing mostly at the under the front of the engine bellypan. Also a small amount of water dripped little more forward (maybe under the seats location) as I was racing at the track.
Had to retire before last two starts and took the car home driving it... while keeping cabin heater on HOT sertting and selecting only highway roads to allow coolant to stay relateively cool - I have a low temp thermostat.
No leaks on the way home for 110km and temp stayed low.

Opened the bellypan under the engine and found out the leak coming from water temperature sensor, but only when the water was at normal or higher operating temperature and the water pressure was high.

http://986forum.com/forums/uploads02...1630296864.jpg

Unless I've missed it, a question or two that haven't been asked: How many miles on the car when you got it? And, to your knowledge, has the WP ever been replaced (by you or the PO)? If not, it's waaaaay overdue.

You do know the low temp therm has absolutely nothing to do with how hot/cool your engine runs, right?

Have you considered snuging up the temp sensor?

:cheers:

Yes, I did get the low temp thermostat to get the water circulation open sooner ;)

I have a new sensor on a way already and will swap it later this week as there is two large water hoses that run right below the motor mount that look like they'll at the end of the life already and I'll swap those as well.

These leaks showed up now as I changed the slightly leaking coolant reservoir last week and the pressure is now staying at the normal level :ah:

So it's not a water pump leak? You've ruled that out?

If that's, by any chance, the original (would seem unlikely, but I think I've heard of them going that long) you should definitely change it out.

2 different things going on. Pilots issue isn't the same (as far as we know so far) as the original posters issue. He was just providing information of where the OP should also look for potential leaks.

Since the OP says the leak is coming from the front it is most likely not a WP issue.

found the leak but need help
 

Hello All,
I finally found time a month later to do this fix, as life got in the way.

I removed the belly pans/splash shield first. Did a coolant pressure test to 19PSI and actually now can see where the leak is coming from. Not sure which pipe this is but it is close to the water pump.

Looks like a T- connector connecting this hose to another hose is cracked and is the source of the leak. The pressure drops from 19PSI to 18PSI in about 5 minutes or so with the dripping.

I have attached 4 images: one from an angle from the passenger side, two from the hose that has the dripping and one that is a good picture of the full crack (red arrow).


- Cracked T-connector
http://986forum.com/forums/uploads02...1632684595.jpg

- Drip from the crack
http://986forum.com/forums/uploads02...1632684640.jpg

- Drip from the bottom of the hose (looks like no cracks here, just flow of coolant)
http://986forum.com/forums/uploads02...1632684725.jpg

- Location of the hose from the passenger's side for context
http://986forum.com/forums/uploads02...1632684756.jpg

I understand that replacing this whole hose and hose connector is needed, which will involve a full coolant flush/bleed too.

What is the interim solution ? Can I JBWeld something here ? I have a PCA meet next Saturday and would like to go for it.

Can anyone guess why the crack happened ? is it normal wear and tear or did the previous mechanic use a bad connector or something ?

Thank you in advance for advice.





Best
VK.

Is the replacement part number in reference to my above post a 4-way hose or a 3-way hose ? I have an Automatic Transmission with Tiptronic.

https://www.pelicanparts.com/More_Info/99610621212.htm?pn=996-106-212-12-M100&SVSVSI=1048&DID=21164 (3-way hose)

https://www.pelicanparts.com/More_Info/99610652204.htm?pn=996-106-522-04-OEM&SVSVSI=1048&DID=11496 (4-way hose)

Four way…….