Coolant leak?

How-to's and repair secrets for your 4WD can be found here. Have a question? Ask it in here!
Post Reply
User avatar
JDNightFox
Top Notch Member
Posts: 151
Joined: Sun Nov 01, 2015 5:39 pm
My tercel:: 1986 SR5 / 1987 SR5
Location: OKC

Coolant leak?

Post by JDNightFox » Mon Jun 24, 2019 6:36 am

My engine bay smells like coolant and the coolant has been mysteriously disappearing but I cannot find a coolant leak anywhere

The overflow bottle also has a layer of what looks like grease on the inside but the coolant itself is completely clean

I have drained and refilled it several times already and the coolant was never dirty

User avatar
NWMO
Highest Ranking Member
Posts: 610
Joined: Wed May 20, 2015 1:08 pm

Re: Coolant leak?

Post by NWMO » Mon Jun 24, 2019 6:56 am

JD,

I would be doing a visual inspection when at operating temp. It may be that the leak is slow enough and in a spot that doesn't get to the ground easily, allowing any leaked coolant to be evaporated before showing itself. Thus the odor, the loss, but no puddling. Here are a few spots I would check first:

- steel bypass tube near thermostat, found a pin hole in mine
- radiator fins may show staining of a leak in the radiator itself
- base of thermostat housing
- hose ends

On a more fatalistic note, if none of the above seems to be the problem, I would pull the plugs and look for any "washing" on the plug ends and piston tops. I would also be looking for white smoke from the exhaust, particularly at start up. I would also pull the dipstick and look for any emulsion (white, milky streaking or coloration in the oil).

Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"

"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain

User avatar
JDNightFox
Top Notch Member
Posts: 151
Joined: Sun Nov 01, 2015 5:39 pm
My tercel:: 1986 SR5 / 1987 SR5
Location: OKC

Re: Coolant leak?

Post by JDNightFox » Mon Jun 24, 2019 9:18 am

NWMO wrote:
Mon Jun 24, 2019 6:56 am
JD,

I would be doing a visual inspection when at operating temp. It may be that the leak is slow enough and in a spot that doesn't get to the ground easily, allowing any leaked coolant to be evaporated before showing itself. Thus the odor, the loss, but no puddling. Here are a few spots I would check first:

- steel bypass tube near thermostat, found a pin hole in mine
- radiator fins may show staining of a leak in the radiator itself
- base of thermostat housing
- hose ends

On a more fatalistic note, if none of the above seems to be the problem, I would pull the plugs and look for any "washing" on the plug ends and piston tops. I would also be looking for white smoke from the exhaust, particularly at start up. I would also pull the dipstick and look for any emulsion (white, milky streaking or coloration in the oil).

Chris
There’s a little bit under the stem of that bypass thing, if it has a hole in it how do I get a new one? Or do I just figure it out

Are there gaskets on it, how hard is it to remove and replace and find new gaskets

User avatar
NWMO
Highest Ranking Member
Posts: 610
Joined: Wed May 20, 2015 1:08 pm

Re: Coolant leak?

Post by NWMO » Mon Jun 24, 2019 10:28 am

JD,

Mine had a hole in it and I sleeved it with a thin wall piece of brass, no problems to date. However, it appears the parts are still available and not ridiculous. I would pull it if I were you and check it out, it may be as simple as leaking past one of the o-rings. Here is a good link and it includes some additional links in Tom's responding post.

viewtopic.php?f=4&t=14002&p=105345&hilit=bypass#p105345

Chris
Psalm 37:4 "Delight yourself in the Lord and he will give you the desires of your heart"

In remembrance of my friend ARCHINSTL:

T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"

"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain

The Professor
Top Notch Member
Posts: 490
Joined: Wed May 12, 2010 6:38 pm
My tercel:: 1987 Tercel SR5 4WD wagon
Location: Western Washington
Contact:

Re: Coolant leak?

Post by The Professor » Tue Jun 25, 2019 8:01 am

JDNightFox wrote:
Mon Jun 24, 2019 9:18 am
There’s a little bit under the stem of that bypass thing, if it has a hole in it how do I get a new one? Or do I just figure it out

Are there gaskets on it, how hard is it to remove and replace and find new gaskets
I just bought the pipe, the O-rings and the housing gasket from the dealer. I think it was around $40 for all four parts.
1975 Subaru SuperStar wagon
1984 Subaru Turbo-Traction wagon
1984 Subaru Turbo-Traction hardtop
1987 Subaru RX 3-door
1987.5 Subaru RX 3-door
1987 Subaru RX Type-RA 3-door
1987 Toyota Tercel SR5 wagon
1999 Subaru Forester S
2002 Subaru WRX sedan

User avatar
Petros
Highest Ranking Member
Posts: 11043
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Coolant leak?

Post by Petros » Wed Jun 26, 2019 6:00 pm

typically you may have a tine pin hole leak that only sprays steam when it is warm and running, once cool it leaves no sign of a leak. those are had to find, you have to inspect the engine while it is warm and running and watch for a source of steam spray (hard to see in day light, using a flash light at night is helpful, easy to see the mist).

if it is the by pass tube, that is an easy fix. replace, or have the tube welded is best, otherwise a patch with lots of RTV might work (consider it is under pressure). gaskets, o-rings, and the tube is still available.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

User avatar
irowiki
Highest Ranking Member
Posts: 3372
Joined: Tue Apr 02, 2013 10:02 am
Location: Farmington, NM

Re: Coolant leak?

Post by irowiki » Wed Jun 26, 2019 7:31 pm

NWMO wrote:
Mon Jun 24, 2019 6:56 am

- steel bypass tube near thermostat, found a pin hole in mine

Also the o-rings on each end of that tend to leak too.

Edit: how odd, the thread only showed the first reply until I replied :?
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)

Site administrator, if something is broken, PM me!

81 Coachmen RV, 70k miles
95 Camry Wagon, 153k miles
04 Camry Sedan, 250k miles

User avatar
MrWrench
Advanced Member
Posts: 65
Joined: Sun Feb 03, 2019 9:10 pm
My tercel:: 1985 Tercel SR5. aka Spud
Location: Michigan

Re: Coolant leak?

Post by MrWrench » Fri Jun 28, 2019 6:21 am

Could always wait until it cools down and use a rental pressure tester from the parts store.
I could smell coolant after my engine rebuild a few weeks ago. I was a little nervous because I couldn't find anything and it was not dropping very quickly from the overflow tank.

The one I rented from AutoZone had a cap that fit our Tercels radiator cap perfect.
Pumped it up to 13psi and found my small leak. It was weeping around the house to the heater core. Tightened the clamp up and all has been well since.

Just another option for ya.
1991 Toyota Celsior RHD
1988 Volvo 780 Bertone
1980 Volvo 262 Bertone - E85 SBC project
1985 Toyota Tercel SR5. Aka "Spud"

User avatar
JDNightFox
Top Notch Member
Posts: 151
Joined: Sun Nov 01, 2015 5:39 pm
My tercel:: 1986 SR5 / 1987 SR5
Location: OKC

Re: Coolant leak?

Post by JDNightFox » Mon Jul 01, 2019 7:25 am

MrWrench wrote:
Fri Jun 28, 2019 6:21 am
Could always wait until it cools down and use a rental pressure tester from the parts store.
I could smell coolant after my engine rebuild a few weeks ago. I was a little nervous because I couldn't find anything and it was not dropping very quickly from the overflow tank.

The one I rented from AutoZone had a cap that fit our Tercels radiator cap perfect.
Pumped it up to 13psi and found my small leak. It was weeping around the house to the heater core. Tightened the clamp up and all has been well since.

Just another option for ya.
That's not a bad idea. I know there's residue around that bypass tube so that's at least one spot. The heater core was another spot but I tightened that hose, it may still be leaking so I might need to replace it

User avatar
irowiki
Highest Ranking Member
Posts: 3372
Joined: Tue Apr 02, 2013 10:02 am
Location: Farmington, NM

Re: Coolant leak?

Post by irowiki » Mon Jul 01, 2019 11:11 pm

If the heater core is leaking you'll know it!
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)

Site administrator, if something is broken, PM me!

81 Coachmen RV, 70k miles
95 Camry Wagon, 153k miles
04 Camry Sedan, 250k miles

Post Reply