I have a 99 TL with 232K. Bought with 20K - owner maintained except 4th transmission (only paid for last one at 220K - $4000 at dealer), and timing belt and water pump done by dealer at 110K and 210K. Car has original thermostat with some deposits around area where it is bolted to engine. Bought OEM Acura Thermostat. Question is that it looks like you need to remove a heater hose to access the 2nd 10mm bolt (bolt closest to firewall - for socket wrench access) As heater hose is lower than the top of the radiator by ~3-4", do you have to drain some fluid from the radiator prior to removing the heater hose and the metal fitting that the lower radiator hose goes into to access the thermostat? (connection of lower radiator hose to metal fitting adjacent to thermostat is also about 3" below the top of the radiator)

https://www.flickr.com/photos/470046...n/photostream/
https://www.flickr.com/photos/470046...n/photostream/

 

even with draining the radiator there is coolant in the hose
this job is messy, place a catch pan under car and hope for the best and expect engine cleaning required
Spray some silicone or wd into the ends of hoses and the clamps
those may be stuck on there like glue!
Potential damage to hoses during removal with implements of destruction exist~

make sure to burp system afterwards using the book method with all its specifics of idle till fan cycles then 2000 rpm till fan cycles etc
need one? free download at www.owners.acura.com need cars vin
good luck!

 

To remove all Coolant you have to Remove the coolant bolt behind the engine block (Just behind the VTEC Solenoid).. That way all coolant goes out! Remember to put the heater at full heat before shutting down the car so it also pumps out the heater core coolant.


The coolant that stays in the top Hose cannot be removed since the T-Stat will close.. In the end of things that Little coolant doesnt affect much since you are putting in almost 2gal of fresh coolant... You can always remove the hose but why bother.. Its almost 1/4 quart.

 

Yeah, as these guys said.....no way around some coolant spilling out when removing the T-stat from it's housing. Just unclamp the hoses to make access easier. May be a good idea to replace the rubber hoses and clamps, unless ya know that they were already done previously.

While unsure about the '99 model, the adjoining ECT sensor and rad fan switch could also be replaced at this time while working in the area. Clean up all mating services, use a new rubber o-ring seal when installing the new Honda 2 stage T-stat. Make sure that the relief pin is oriented on top. Clean up or replace the mounting bolts and insure that the threaded receiving holes are good. Anti-seize the first couple threads of the bolts before tightening the T-stat cover down @ 12 Nm / 8.7 lbft.

 

The radiator hoses are original. They look fine from the outside and are pliable when squeezed with no cracks or leaks. Do you know if they degrade from the inside and should be replaced because of that reason? I am planning to give the car to my son as a "legacy" car and plan on taking it to 300K. Would you bother with replacing the radiator hoses, as it appears you can just remove the (2) 10mm bolts from the metal housing that the lower hose attaches to adjacent to the thermostat and change the thermostat without removing any of the radiator hoses?

 

change them now, with new style hose clamps too
hoses do go bad from inside and send rubber bits into places it does not belong and will wreak havoc
hose can even suction itself closed! try and trouble-shoot that one!!

10 years is a really good rubber hose life, every year after that is borrowed time
Do you want the inevitable late night phone call about some weird smell, and the temp gauge redlined?
ck the heater core hoses while you are in there

 

The way I like to do it is to have the dealer just get ALL the coolant hoses. You might be surprised at how many there are. I can't tell you off the top of my head what our cars take, but an early 90's 4 cyl. accord has 17 coolant hoses if I remember correctly. The oe ones usually fit better, and don't require cutting to fit.

 

Thanks for the replies. I just ordered the radiator hoses and clamps from an Acura dealer online and will let you know how the repair goes. I think I will hold off on the heater hoses for now. I will send photos of the old thermostat for those interested in seeing an original 99 TL thermostat with 232K miles of service.

 

Replaced thermostat, both radiator hoses, Fan A sensor, and ECT sensor today. Photos of parts with 232K and new in links below. Also photos of very useful funnel to fill and "burp" the radiator.

https://www.flickr.com/photos/47004606@N00/14813808772/
https://www.flickr.com/photos/47004606@N00/14813825502/
https://www.flickr.com/photos/47004606@N00/14813823572/
https://www.flickr.com/photos/47004606@N00/14811088631/
https://www.flickr.com/photos/47004606@N00/14811088631/
https://www.flickr.com/photos/47004606@N00/14627541848/
https://www.flickr.com/photos/47004606@N00/14627634777/

 

Should have replaced the whole radiator unit while your at it that green mold/mildew... possibly corroded radiator....=)

 

what often happens is coolant additives go bad after 3 to 5 years, they turn acidic in an aluminum environment = not ok
Its not something that gets thought about changing since oe coolant went 7 years...
book actually says no more than 5 years after that first change... some years age~

did you fully drain the engine block by removing or opening its drain valve- located near cv- exhaust pipes at rear/firewall side of engine

I agree with above post- all that crud growing out or inside of things is a clue
run a pressure test and make sure seams are good on the rad, when you fix other small leaks or new functioning cap, the increased pressure
can show up in weak seam seals on rad

 

Yeah, while MikeND's '99 TL presently has 232k on the dial, it's had the T-belt replacement servicing done at 110k and again at 210k. It's difficult to believe there's that much crud built up within the system, especially assuming that during the T-belt work..... the new coolant used was the right stuff.

This is why it's worth considering the replacement of other things like the T-stat, hoses and drive belts when the coolant was drained with the T-belt service. Anyways, hopefully the system was backflushed to clean out the rad and block's passageways. Wonder what the heater core looks like inside ?

 

All prior timing belt and water pump changes were done at the Acura dealer. Drained all antifreeze from the radiator and the engine block block, and it came out clean. (It had only been in there for 20,000 miles since the last waterpump/timing belt change). Radiator was squeaky clean inside. Replaced fluid with approximately 2 gallons of new Acura fluid – approximately $40. The inside of all the old radiator hoses were clean, except for the deposits near the end of the one radiator hose that went to the housing near where the thermostat had been previously leaking – see first post photo link. Below are two links to photographs after the job was complete. The first photo shows the upper radiator hose and the new Fan A sensor. The second link shows the same top radiator hose and the new ECT sensor. Thanks for all comments - makes repairs much easier with the expert recommendation of those who have previously done the work.
https://www.flickr.com/photos/47004606@N00/14634301500/
https://www.flickr.com/photos/47004606@N00/14817917391/

 

My 99 tl occasionally overheats but not to full extent. Might have to do all these checks.

 

any temp change, and running more than halfway on the gauge and dead steady are bad signs

STOP driving until its fixed,,can only cause damage by driving with elevated temp reading

not much to ck on the TL , coolant level , res bottle level- hose on cap in bottle is on firmly, hose condition, water pump failure

What driving scenario leads to symptoms?
what are your symptoms, we can narrow down the search for you