FUNrunner87

I have a 99 tacoma 3rz that has about 135k on it. I have been loosing coolant for the past 6-9 months. I can not find the leak. I can run a tank of gas threw the motor and go from having a full resi to just a few drops. I dont see water leaking anwhere. Is there any common places it could be leaking that im just not seeing? I want to do a Compression test but cant find my tester... would that be a valad way to check the HG? I see the normal white smoke on cold starts, it goes away after a few miles though. I see some water dripping from the exhaust once its been running a wile (5mins +) but thats normal correct? I have pulled the dash and inspected the heater core even though the passanger floor was dry. It looked brand new and I cant see anything pointing to it leaking. I dont really know where to start from here.. I need some pointers. Any help is great!!!!!

brian2sun

I would do a compression test like you mentioned, and if that doesn't give you anything to go on, you can do a leak-down test too. A cooling system pressure test can be done also. Is the engine missing/stumbling or have you lost power?

FUNrunner87

The engine does not miss that I have heard, but I have not been listening for it. It still has the same ole power as before. I dont have any codes and the Cel light works (per key turn test)

I Dont find any coolant in the oil. If it was a leaking head gasket it would bubble up in the radiator correct? I should be able to take the cap off once its cold and let it run at idle. Once the thermostat opens I should see bubble if thats the problem.. Correct?

NwRunner

Ive been having the same issue in mine for about 2 years now. although not as rapid, ill lose about a resi every 2 weeks. I ended up changing my HG because of it but it didn't fix anything. Try looking at your water pump, I mean really looking at it. a slow leak from there could.

Also check the water return pipe located on the back of the motor between the head and the firewall.

profuse007

radiator crack are hard to find. I would start there.

FUNrunner87

Is there any place they like to crack, or is it a random thing? what are some ways to check it in the truck??

snobdds

Pressure test your cooling system. That should show where it is leaking from. It that is normal, then I would do a compression test. Those two test should tell you what you need to know.

FUNrunner87

A small update on progress. I pulled the radiator cap and let it run for a wile. I watched for bubbles. The coolant level slowly came up and slowly started to run over. I saw one or two bubbles but nothing that looked wrong. I pulled the plugs to see if maybe if one plug looked clean showing signs of a leak. All 4 where nice and tan and looked great. I guess the next step is to find someone with a pressure tester.