Greetings from newby. 2001 overheating. Would appreciate some info, I'm at my wits end! (1 Viewer)

[jaimero]

Howdie fellow enthusiasts. My first post and hoping for some info. My 2001 with over 302K miles, meticulously maintained by me (I've been wrenching on my cars since 1979, always oem parts, best practice method etc.,) suddenly overheated when my wife was driving it. I mean full red on-the-dial overheat with steam volcano etc. happened couple blocks away from home so waited til it cooled down and then refilled radiator and drove home uneventfully.
Over the past 10 days I performed the following:
1. new radiator
2. new radiator cap
3. new water pump
4. new thermostat with gasket
5. new timing belt/ rollers/tensioners
6. new coolant

Car still overheats! Its real overheating, not a dial/gauge problem as there's hot coolant puking through the rad cap and into the plastic overflow tank. Head gaskets seem ok (No water in the oil, No oil in the coolant).

Observations: after careful refill of coolant and burping, the temp climbs suddenly after driving about 4 blocks. temp remains high and close to the red zone, but I'm able to get it home before getting in the red zone. The Top inlet rad hose is now hell of hot. The overflow tank is nearly full with evidence of splashed coolant around radiator. Lower rad hose is relatively luke warm. Seems there's a blockage......

So, I remove the new thermostat, gut out the old thermostat so there's no obstruction, repeat my drive. Now there is flow, I have normal temp as long as i drive under 2k rpm's around the block for short periods of time. However, If I then drive above 2K rpm's at steady rate for about a mile at about 45mph the temp starts to climb again, forcing me to put on heater to release heat through the heater core. With the gutted thermostat I can drive through out the city with normal temps as long as I allow some periods of idle to allow radiator to cool down by slowing the velocity of the coolant through the radiator. Seems strange. This whole thing.

My wife wants me to get rid of the LC but I purchased it new and has been a family member to me......

Any help appreciated.

Jaime

 

[Trunk Monkey]

Fan clutch and fan bracket? Any obstructions to coolant passages? New hoses?

Be careful driving it and using the cluster gauge as the indicator for overheating, it's notoriously vague. By the time it reads red you're well over 220*+. Better to use a OBD reader.

 

[ramangain]

How about installing a flow gauge before and after the radiator on a couple of used/ratty coolant hoses you can modify for the gauges?

 

[MJK]

Sounds like a flow restriction or a head gasket.

All this stuff you replaced.... all at once or one thing at a time following the initial overheat? I'm wondering if there was any aftermath from the previous overheating that perhaps clogged up the new radiator passages.

Fan clutch may well have caused the initial overheating, but if the truck won't stay cool at 45mph with a gutted thermostat I think there is more than that going on now.

 

[jaimero]

Thank you all for your input. Yeah, did all new stuff at once. Its like there's an obstruction inside the block. Is this possible? I have noticed at times, since the initial overheat, sometimes even tho the LC temp is at 190 degrees (real time analysis thru obd2 code reader), there's very little hot air coming thru vents when cabin temp placed at maximum heat and the lower radiator hose is cool, Like, again, there's an obstruction of water thru the block.

Question for the gurus: can a bad heater core affect the block coolant circulation such that the car overheats?? Seems like an engineering flaw and I don't think Toyota would engineer it like this but thought I'd ask....

 

[MJK]

I'm no guru, but I have dealt with an overheated 3UZ. The weak heater sounds more like a symptom than a cause to me. You can pinch off/eliminate the heater hose loop at the back driver side of the block and everything should run fine in a normally functioning truck (apart from the heater, obviously).

How did you drain the old coolant? Block drains? Did you see any evidence of contaminants in the coolant or obstructions?

Are you SURE you got it bled properly? Ran the front (and back if it has it) heaters, left it idling with the funnel bubbling, etc.? Ideally with the nose up?

If you are stuck, start by eliminating things.

• Vacuum bleeder should help with bleeding, if you think that is suspect.
• Compression & leak down for cylinders, or coolant pressurization should test HG.
• You could remove the rad and stick a garden house in it to confirm proper flow through it

 

[medtro]

the lower radiator hose is cool

This sounds like a clogged radiator.

 

[Skidoo]

Going to vote clogged or defective radiator. Because its expensive and new doesn't always mean its good.
Disconnect radiator hoses, connect a garden hose to bottom of radiator with some kind of adaptor and see that you get high flow and no crud coming out the top connection. If you are not getting flow through it, be careful as there is more pressure than the radiator can stand.

 

[KillerBox]

I purchased a 1998 Tacoma TRD 5 Speed 4x4 in 2013 that had 18,000 miles on it that was owned by a 60+ year old man.

I spent the first month sparsely driving while baselining it on the weekends. Come to find out the previous owner sold it because it had a reoccurring overheating problem but, he didn't tell me about it.

I switched out fans, anti-freeze and thermostat. Water flowed well through it too. The problem was the truck had mostly been driven on a dirt road that was about 5 miles long. All the fins were coated and rock hard with fine dust that you couldn't even really see (we aren't talking about blotches of mud that people get when they go mud riding). I high powered washed the fins out a few times and the truck ran perfectly with no more overheating.

 

[jaimero]

Thank you for the info. So, today I double checked the radiator:

-disconnected upper hose at the radiator and plugged it with plug that comes with new radiator. Good thing I saved it!
-disconnected lower radiator hose at the radiator and pushed hose aside so I can see flow from above
-pinched off overflow small caliber hose that feeds overflow tank
-placed water hose into usual opening on top and ran the hose full blast. Absolutely no back pressure, large caliber water exiting below!

Conclusion: New radiator patent (open, not obstructed, free flowing)

Next, I removed all spark plugs (but forgot to remove fuel injector connections) and ran compression testing.
These are the pressure with corresponding cylinders:

arranged in firing order:

PSI cylinders PSI
----------------------

145 8------7 150
105 6------5 102
125 4------3 187
130 2------1 182


Im sure at 302K the engine is tired, and a few of these pressures are really off! Surprisingly, despite having what sounds like a discharged lifter tick, the engine runs pretty smoothly!!

Could I have engine blow-by? maybe my valves are allowing too much heat thru the valve stem seals??

Now, I could squirt in a bit of oil into cylinder to improve sealing at the rings, and thinking about this, it didn't help that the injectors were spraying into the cylinders during the test. Should I repeat testing with injectors off and a squirt of oil into each cylinder or is this as good as it gets?

thank you all!!

Jaime

 

[MJK]

If those results followed this procedure, then that is not a good result at all.

Edit: Does your camera fit in the spark plug holes? If so, how do the cylinder walls look?

 

[jaimero]

Well, Took it to an independent shop, they said they verified combustion gasses in the coolant. Apparently could be a head gasket or even a head issue including possible head cracks, but also pitting on the block?

Looks like a teardown of the engine. Question..... how do-able is rebuilding This engine by someone (me) with above average ability? Is it hard? Are specialized tools needed or complex maneuvers? I know I can send the heads to a head shop. They will rebuild them for 450 bucks. But, what special treatment, if any, needed on the block. Will need to pull engine and do front/rear seals, new bearings, hone the cylinders new rings etc.,

I mean, I use to do this with my dad in high school, but those were cars of the late 60's and 70's. A bit different from my 2001 LC.

Anyone know good place to get master engine rebuild kit??

Thanks a million
Jaime

 

[abuck99]

At 300k+- you may be better served to get another used or jasper rebuilt engine rather than trying to rebuild. The cost to swap motors is generally less than teardown and rebuild.

 

[FxFormat]

As soon as i read "hot coolant puking from radiator cap into reservoir" i knew right away you have a head gasket issue. Sorry but maybe look into a used engine with lower miles

 

[jahawk]

This stuff works amazing and you've got nothing to lose. I picked up a supercharged 5.0 cheap a few years back with a HG issue throw this in and after a few minutes the car run perfect. I had the car for a couple more years without issue.

Amazon product ASIN B000NOO798

 

[jaimero]

So, I decided to tinker around with the engine this winter. I will need a master overhaul kit/set. Anybody know of a good, reputable brand? I know that for the actual head gaskets I will purchase straight from Toyota dealer.

thank you in advance