A question of balancing risks in the West...

The Patient

• 1997 Tacoma, 5VZFE v6, 233,000

Patient History

• Continuous proactive maintenance
• Radiator failure 2,000 miles ago (first breakdown ever)
• Engine temp spiked hot, pulled vehicle quickly and got towed
• Radiator replaced

Current Problem

• Since radiator replacement, coolant drawdown at a rate of 1 reservoir per 2,000 miles
• Radiator has bubbled over into reservoir twice after use of 4wd
• Add'l info: no visible leaking, engine temp indicator holding at spec

The Main Issue
I have to drive from Bishop, CA to central Idaho this coming weekend (700 miles). Cold climate driving, numerous moderate elevation passes, essentially no services

The Questions of Risk:

1. What do you think is wrong?
2. What diagnostic info can I get a mechanic give me right now that would help?
3. What is the risk??

Thank you!!

 

1. Head/head gasket.
2. He'll test the coolant and will find exhaust gasses in it.
3. You'll die in the mountains

 

Drop another motor in the bitch by Friday.

 

Yeah the head seems to be the consensus, and my wife and I are agreed on an engine swap as opposed to junking her. Question remains, how far has this problem progressed, and can I expect to pull 700 miles more based on current symptoms?

 

Will the truck sit and idle for 15 minutes without overheating? If it doesn't overheat I think you can use Bars Leaks Head Gasket and Cooling system sealant (but don't trust your life to my opinion!)

 

Yes. Temp indicator holds at spec, and radiator doe not bubble back into reservoir after shutdown.

To gauge severity of problem Ive been told to get a leak down test and a cooling system pressure test - true? Dealership calls it a 'block test' for $200. A test that gauges the problem could be helpful. A test that simply confirms the head problem is a waste of $.

Thoughts?

 

Take it to a radiator specialist for your $200 test and save $150.

 

Useful advice, thanks gents.

 

Heads can warp pretty easy with an overheat, and it may have been getting a lot of heat before you notice the problem. A gasket can be damaged in pretty short order as well. There's no way to say that it will last x miles and fail at Y. Assuming the gasket is going it could hold on for a year, it could fail the next time you start the truck. If the head is warped, eventually the gasket will fail where the warp is. You may not need a new engine, you may not need a head, the only way to tell for sure is to pull the head and check it. Once you pull the head, no matter what, you'll need a head gasket. With mine I pulled the head thinking I needed a gasket, found the head was cracked, and decided against putting a new head on an old engine so did the swap.

 

Indy, come repair time what do you think of doing a full swap if it proves to be only the gasket? Our rig is at 230,000 and we've decided to re-invest in it. Our thought is the swap (including tranny) is worth it, so we can be confident it will run to 400,000k.... Thoughts?

 

How many miles on the waterpump?

Worn impellers don't circulate the coolant effectively. You wouldn't see an issue at idle but under heavy load it would show up.

How are you determining the issue is not being indicated by a fluctuation of the coolant temp. I would not rely on the gauge in the dash. An OBDII scanner that can read the ECU data would be a much better indicator. UltraGauge? ScanGauge?

 

55k on the water pump, replaced concurrent with timing belt and thermostat. Radiator thermostat also replaced with recent radiator failure. It's possible it was damaged when the radiator blew, but probable?

As yet there is no direct evidence to support head warping or gasket breach, just informed guesses that that is the likely culprit. I assume the only reason the engine temp indicator remains at spec is because the cooling system is (at present) successfully compensating for the increased heat load from an engine problem.

Pressure test of cooling system tomorrow. Hope to deduce whether leak is external or internal....

Oh and GO HAWKS

 

If the head is ok, I'd do the gasket and wouldn't worry too much. The truck I had, around 260k on the clock if memory serves, too many miles for me to want to put a new head on it. And my head was trash so just milling it flat and reinstalling wasn't an option.


Besides it shooting all the coolant out as soon as I put in a thermostat it ran really well. The head gasket is a pain in the butt, but $ should be quite a bit cheaper than a full swap. Off the top of my head I ended up with about $2k in the engine swap (new clutch etc) doing all the work myself. I'd budgeted a couple hundred for just the gasket, included random bits and piece to replace on the way.

Unless I was having transmission issues, I wouldn't think about replacing it. Throwing money at it just to throw money at it.