No coolant , no visible leaks

Hello i have a 1996 tacoma, today i drove this truck not 15 miles when i saw my temp guage all the way past the H for hot. I pulled over and saw no visible coolant leaks It was bone dry out of coolant none what so ever . I assumed the thermostat was the issue so i went and bought one along with some coolant. I just had this coolant flushed maybe a month ago by a local shop and drove it 3-4 times since and have had no problems. I filled the coolant started it and drove a good 20 miles problem free with the temp staying steady right where it should be. There was a leak i noticed on my grill guard , it was comming from the the connection where the resevor hose was attached to the radiator. I tightend the hose clamp n ran it again fine without leaking. Im very curious to know what this is all about . Any help at all will be very much appreciated. I was told a new radiator cap would be a good idea to buy (from a guy i know), being they go bad (so im told) and it could have somthing to do with it. Where could have all that antifreeze went ?

 

yeah radiator could be the issue..get a new cap and see if that helps..sometimes if it doesnt seal right on the cap it can cause it to leak.

 

keep an eye on the exhaust - if it starts to smoke and smell like antifreeze - head gasket here we come!!!!

My money's on the radiator cap tho....

 

Was the entire radiator missing coolant? Or are you talking about the resevoir tank?

Did you check the radiator & fluid after the guys did the flush?

Since the guys at the shop did a flush....I'm wondering if they either didn't put enough in or didn't 'burp' the system enough and you still had air pockets in the system. You mentioned you drove it 3-4 times since that was done - were they short trips or long trips?

A new radiator cap is cheap insurance - however, you'd probably notice signs of it leaking.

When was the last time you had your water pump changed? If you haven't changed the water pump, you might have a leak where the pump attaches to the block. When I owned my 96, I continued to lose fluid for about a year before I noticed where the leak was from.

 

Hey guys im sorry about the not so detailed original post. Was in a hurry to get the problem solved being its my everyday vehical. so......... The coolant was flushed, after being flushed i checked and all looked good. i put on about 200 miles then one day at random my taco was overheating with no visible coolant none in reserve tank no sign of any in radiator as if it boiled out or something i saw no visible leaks. I assumed the stat was stuck . But before i stuck a new one in i filled the coolant levles. drove 80 plus miles problem free. The water pump is still original . I almost wonder if they didnt turn the heater on when they flushed it and let it circulate to the heater core if im right on the assumtion that the heater core holds about a half gallon or so of coolant.. . I cant recall for certain if i turned the heater on the day it overheated but in all honesty im thinkin i did being its cold up north here. It was a strange experince it went from fine to overheating then back to fine after filling coolant . Like i said ive put on 80 plus miles problem free since filling coolant . Im kind of stumped but some how all seems well have had no issues since filling coolant .......?????? Thanx to evryone. Still open for possible answers id just like to know what that was about... Again thank you

 

I betting that the guys that flushed the coolant didn't do a good job filling the cooling system by getting all the air out. You are probably good to go now but keep a eye on it.
If you lost that much coolant you would smell a strong antifreeze odor.

 

I would guess this too. Had this happen before.

 

Thanx for the help all

 

Well bad went to worse. Was out in the garage today, and i become somewhat obsessive about issues reguarding my truck. I started the taco up and noticed how much coolant i had lost, then noticed the smoke comming out of exhuast along with drip after drip after drip of water .. . . . So i then checked the oil n its frothy and i popped open the oil cap and saw a peanut butter like substance formed all around the cap.. So based on that info im guessing its gota be a head gasket or a bad head . Id really like to think its the gasket but honestly im not sure. Does anyone have any thoughs or suggestions about where to go now? Thanx all.. . . . .. .

 

Take your truck to a mechanic.

 

sounds like head gasket time

 

Well, dont assume the worst yet.

The peanut buttery oil cap could be normal for your trucks age. The smoke and water could have been condensation.

Do a compression test.

 

The only way you're gonna know for sure....is change the oil. If the oil has coolant in it, then...you can assume it's the head gasket and hope all that overheating didn't screw something else up in the process.

Do you know if your truck had the head gasket recall done? There was a recall for the head gasket on the 1st gen trucks - as they had lots of problems especially on the 3.4L. If not...then I'm really not sure if you can pursue this through the dealer for minimal cost or if that recall has expired based on the age of the truck.

Have you had the truck inspected for frame rust? You might be wishing the truck would fail the frame rust warrantee instead of having to pay $$ to fix these new problems.

 

Janster, I believe you are referring to the 3.0 v6 (3vz) head gasket campaign.

 

The early tacomas 3.4L had the recall also.
http://home.4x4wire.com/erik/t100/3.4v6_headgasket.htm

 

Does your exhaust have a sweet smell to it?

2nd this motion and like to suggest a leak-down test if you have the equipment.

The early 5VZ did have an issue with the head gasket though it wasn't to the extent of of what the 3VZ experienced.

 

Getting a little off topic, but anyway...

The 5vz head gasket problem wasn't a recall like the 3vz (unlimited miles/age). It was a TSB, which is only effective within warranty. Since all 95-97's are out of warranty, the TSB no longer applies.

 

Yeh exhuast sweet smelling and there is coolant in the oil. So tomarow im going to go to the toyota dealership and see if there is anything they can do. Im hoping to get it fixed for free but im not counting on it. Worth a try .. . . . .Thanx all

 

Head (suck) or Intake gasket (cake compared to the head). Not very familiar with those setups.

How's your oil level? High? Low?

I thought typically, espeically with V6 engines, if you had more of a head problem, oil would be leaking into the coolant and this would be visible in the overflow tank, radiator. Brown milkshake in the radiator.

With that, coolant leaking into the oil would more be a intake gasket leak. Loss of coolant, what is visible is regular color, no visable leaks, brown milkshake oil. Watch this though, coolant will destroy the bearings and such in the crankcase.

 

So,
Up until today I was beaming with joy being the owner of a shiny new (to me) 99 trd. I then noticed a coolant smell, and after adding some over the last week I know that it is in fact losing coolant quickly. It doesnt drip coolant, it only comes out when the truck is running (ie under pressure) It does not seem to be burning coolant, the exhaust smells fine. I mostly smell it around the truck after it has been running, and to a lesser degree in the cab. I have put about a gallon of coolant in the truck in the last week, so it is going fast, maybe getting worse. I have not noticed any coolant in the oil either. I can run the heater without smelling coolant so it seems the heater core is fine. I have looked for the leak and I found drops on the top of the transmission near the back of the engine. This leads me to believe that it was a water pump or a hose. Since I was unable to find a leak I took it to a mechanic today planning on having them replace the water pump. The mechanic did a pressure test, found that it was in fact leaking coolant quickly. They said it wasnt a hose or the water pump, put a scope around the back and couldnt find the source, now they are taking the intake manifold off, to see if in intake gasket is the issue, then they were talking about a head gasket, which doesnt sound right to me given the symptoms, and would of course be a big deal. I am stumped, and I am hoping that someone out there has had a similar problem and can give me some info that can help me not pay thousands of dollars for a head gasket. Thanks all!