Good Challenge For The Loc

[Gumart1]

In June I had a former Lexus Tech who owns an independent shop locally change my timing belt, water pump, idlers, tensioner, spark plugs, fuel filter, coolant resovoir cap, tranny and diff. service on my '98LS. After the service I noticed that the engine temp ran hotter than before (halfway up on the temp gauge). I waited because I thought it might be air in the system and the coolant just needed to circulate. Never got too hot.

In July my starter went out. Had that fixed and the car starts great every time. Weather is hotter now, and the car wants to overheat, almost to the red mark but cools when I am moving fast. I'd be surprised if the new water pump or thermostat were bad (and hopefully the tech did install the new part, he did give me the old back). I suspected that the coolant wasn't mixed right, so today I started to drain the coolant. I followed the procedure in the Lexus Shop Manual, removed the resovoir cap and fill cap, and drained the 3 drain plugs under the car which all drained nicely, nearly 2 gallons, BUT, the coolant remained in the resovoir to the top. So I pulled the lower hose from the resovoir, and was surprised that it didn't flow from there. I ran the engine with the heater on high temp to open the heater valve and hopefully pull the coolant out of the resovoir - still didn't budge.

Second issue...when the engine was hot, I got no heat from the vents when set to high/hot, just room temp. AC works fine. I did not have this problem before my repairs.

When I moved the heating contols to cold and back, I could see that the heater control valve had moved.

Not sure where to go from here. I did remove the radiator and cleaned it but it wasn't restricted much at all. I can take the car back to the mechanic but would much prefer to solve this myself. Any ideas?

[TA in KC]

You could try a different thermostat. I would just take the car back to the mechanic and let him figure out the problem.

[python]

if your car is getting hot at idle but cools down when u r driving it sounds like the fans are not working....when it starts to get hot,get out of the car and see if any of the coolant fans come on

[Bali26]

Its normal for gauge to be at midpoint.

You ran the engine without coolant in it? ! All you had to do was replace the thermostat.

[Gumart1]

Bali, I know it is normal at the halfway point, please read my post, I am near the red. I'd love to believe it was just the thermostat, but remember that the coolant won't come out of the bottom of the reservoir even when I tried to attach plastic tubing and forcefully drain it out. Also, I get no heat through the vents even with a hot engine. And, it was an OEM part installed just 2 months ago. Sure, it still could be that, but I'd be surprised.

Also, I both fans, the smaller one at the front of the car, and the larger fan after the radiator, work fine.

[Bali26]

Humm maybe your coolant is not circulating for some reason. Water pump? The radiator inlet and outlet hoses should get very hot when thermostat opens up and coolant starts flowing though. You should just let the mechanic deal with it since it started after timing belt replacement.

I was just suggesting to look at the simple things first.

[Gumart1]

I appreciate the suggestions. The reason I am avoiding bringing the car back to my mechanic is that I was so dissapointed to find out out that the guy who serviced the car lost a bolt and a nut for the engine cover, and left me with so little coolant after the timing belt change that the reservoir was totally empty when I returned to him the next morning. This was the only shop near me that specializes in Lexus, Toyota, and Scion only and is run by a former Lexus Tech. The service tech also admitted to me that he didn't use anti-sieze compound on the spark plug threds...great.

I do have a 12 month labor warranty but I bought the parts 3 1/2 months ago from Sewell so I'm not sure how that will work.

I will change the thermostat for kicks and refill the coolant tomorrow; I can't imagine a 3 month old water pump being bad, I did get the old parts back, but if they were really clever, perhaps they didn't change my pump and gave me another guy's old one!

Today I attached a piece of tubing to the lower outlet on the coolant reservoir and sucked to start the draining, but even with the force of my mouth the coolant wouldn't budge. This doesn't seem right? Wouldn't it flow freely from the bottom and isn't that the route into the engine?

Also, I don't understand the relationship to the room temp air from the vents when the heat is on hot and the engine has warmed - does this specifically point to anything?

[python]

i will tell u how it works as i was a service writer....the labor is covered for 1 year, meaning they gaurantee their work not the parts, so if any parts fail its on you, but, if any of their work is at fault then its covered

[IS400]

I wrote up my DIY waterpump/timing belt repair. In it I mention the thermostat has to be installed properly. There is a little loose piece with a hole that has to be oriented right. If it is not installed properly is could be contributing to the problem? Lexus warned me when I picked up the thermostat to install in right and not just toss it in the first way that it fits. Just a thought. Good luck!

[eatingupblacktop]

I appreciate the suggestions. The reason I am avoiding bringing the car back to my mechanic is that I was so dissapointed to find out out that the guy who serviced the car lost a bolt and a nut for the engine cover, and left me with so little coolant after the timing belt change that the reservoir was totally empty when I returned to him the next morning. This was the only shop near me that specializes in Lexus, Toyota, and Scion only and is run by a former Lexus Tech. The service tech also admitted to me that he didn't use anti-sieze compound on the spark plug threds...great.

Did he offer references (what dealer he worked at previously)? Just telling you that he's a former Lexus tech shouldn't be enough. If he left under good circumstances he would tell you where he's been. If It's your first time to his shop, what's the basis for trusting/believing him? The kind of oversight you mention should give you some doubt.

I will change the thermostat for kicks and refill the coolant tomorrow; I can't imagine a 3 month old water pump being bad

Let us know if it anything changes. Even if the new stat was installed properly as IS400 correctly mentions, was it tested prior to installation? When the engine's been opened up that much, making sure the replacement components going in are all functioning as they should is definitely worth the bit of extra time.

[Gumart1]

I don't own a temp gauge to test the existing thermostat but I did see that it was installed facing the correct way. I'm going to pick up an aftermarket stat and will test it today and post the results. I agree it's unlikely but possible that even a new Toyota stat could be bad. I'd hate to think that the water pump is the culprit. It ran hotter than halfway for a month after the timing belt service, but did not venture near the top until after my starter repair was done. I wonder if this is coincidence or if something was re-installed wrong in the starter repair. Or could a blocked heater core happen this way? Again, is it normal that coolant wouldn't flow freely from the bottom of the reservoir with the bottom reservoir hose off and some suction applied?

If the stat change doesn't help today I am bringing it in tomorrow and staying with the car and will post the result. Thanks

[Gumart1]

I tested the thermostat today and although I didn't have a thermometer to get the exact temp, it did open up just before the boiling point, and closed again when it cooled. After checking again, my heater inside the car seems to be working fine. Made sure the thermostat was properly installed, and added 50/50 Toyota red coolant and distilled water again and ran the car. Confirmed that both upper and lower hoses are getting hot, and both fans are working properly. Still runs very hot at idle and I needed to kill the engine before it gets too hot. My biggest concern is I can't understand why the reservoir isn't dropping or raising it's level with the engine running or after it cools even though the heater valve is in the open position.

[N.C.O.]

I tested the thermostat today and although I didn't have a thermometer to get the exact temp, it did open up just before the boiling point, and closed again when it cooled. After checking again, my heater inside the car seems to be working fine. Made sure the thermostat was properly installed, and added 50/50 Toyota red coolant and distilled water again and ran the car. Confirmed that both upper and lower hoses are getting hot, and both fans are working properly. Still runs very hot at idle and I needed to kill the engine before it gets too hot. My biggest concern is I can't understand why the reservoir isn't dropping or raising it's level with the engine running or after it cools even though the heater valve is in the open position.

Did you try back flush the reservoir?

Your description of your problem seems to point air trapped in your system; one of the symptom is no or little heat from your heater at idle. The reservoir need to flow both ways to properly bleed the system.

N.C.O.

[Gumart1]

Thanks for the input all. N.C.O., you were right! The issue was air in the system. My tech bled the system today using a large funnel in the water inlet while the engine was running. Took a good 20 minutes. Running perfectly all day with the temp gauge steady on the 2nd line up from the bottom.

When I did the drain and fill I followed the steps in the shop manual perfectly; apparently this did not displace the trapped air.

My final reflection is that perhaps when the first tech did the timing belt change there was some air in the system because it ran a bit hotter than normal, and when my starter was changed more air was introduced when the hoses were off for the intake removal.

I knew something was up with the reservoir not draining with that bottom hose off, even when I tried to force it.

[IS400]

After thinking about this for a few days I remembered that mine gave me a scare too when I replaced my water pump and timing belt. It started to spike the temp gauge during my first start up and I then tried to fix this and the lack of heat in the cabin by placing the car on a dramatic incline to 'burp' the system. That did not work. I let the car sit, then after it was cool I took off the connector by the thermostat (don't remember which one) and then ran the car and watched it bubble and observed a drop in the coolant level almost immediately. I added more coolant mix (to the connector I detached) and found the car then had heat in the cabin like before. So many other things going on at the time I almost forgot that little snag... again I hope this helps.

I'd call lexus and ask them how they fill the system and advice on burping it too.

[Alexander the o.k.]

Thanks very much for taking the time to post the solution Gumart1. So few people ever bother to post back once they've found the solution, and so, none of us learn a thing. So, Kudos to you, and of course to NCO, for setting you on the right track.

Congrats!

[rtd111]

Thanks for the input all. N.C.O., you were right! The issue was air in the system. My tech bled the system today using a large funnel in the water inlet while the engine was running. Took a good 20 minutes. Running perfectly all day with the temp gauge steady on the 2nd line up from the bottom.

When I did the drain and fill I followed the steps in the shop manual perfectly; apparently this did not displace the trapped air.

My final reflection is that perhaps when the first tech did the timing belt change there was some air in the system because it ran a bit hotter than normal, and when my starter was changed more air was introduced when the hoses were off for the intake removal.

I knew something was up with the reservoir not draining with that bottom hose off, even when I tried to force it.

I am in the middle of a similar problem: temp gauge goes red, no heat, loss of coolant (escaping from around the radiator I believe).

However, its on my 94 SC400. If you care to read it (THANKS), ref: http://us.lexusownersclub.com/forums/index...mp;#entry337775

Problem remains unsolved. Note that I had not had TB/WP changed -- this problem started one fine day.

I have search both LS400 and SC400 forums -- this thread seems to be most promising.

QU: How do you remove the air in the coolant system?

Request: if you read my posting on SC400 forum, any ideas / suggestions?

[rtd111]

Its been quiet... any thoughts? Thanks in advance.

[hlpyfix]

In June I had a former Lexus Tech who owns an independent shop locally change my timing belt, water pump, idlers, tensioner, spark plugs, fuel filter, coolant resovoir cap, tranny and diff. service on my '98LS. After the service I noticed that the engine temp ran hotter than before (halfway up on the temp gauge). I waited because I thought it might be air in the system and the coolant just needed to circulate. Never got too hot.

In July my starter went out. Had that fixed and the car starts great every time. Weather is hotter now, and the car wants to overheat, almost to the red mark but cools when I am moving fast. I'd be surprised if the new water pump or thermostat were bad (and hopefully the tech did install the new part, he did give me the old back). I suspected that the coolant wasn't mixed right, so today I started to drain the coolant. I followed the procedure in the Lexus Shop Manual, removed the resovoir cap and fill cap, and drained the 3 drain plugs under the car which all drained nicely, nearly 2 gallons, BUT, the coolant remained in the resovoir to the top. So I pulled the lower hose from the resovoir, and was surprised that it didn't flow from there. I ran the engine with the heater on high temp to open the heater valve and hopefully pull the coolant out of the resovoir - still didn't budge.

Second issue...when the engine was hot, I got no heat from the vents when set to high/hot, just room temp. AC works fine. I did not have this problem before my repairs.

When I moved the heating contols to cold and back, I could see that the heater control valve had moved.

Not sure where to go from here. I did remove the radiator and cleaned it but it wasn't restricted much at all. I can take the car back to the mechanic but would much prefer to solve this myself. Any ideas?

hi, hope you check the clutch fan should be hard to stop with a rag or a glove on your hand when it's hot???