Nacho_ZR1

So we changed out the coolant last night. Slowly, we began adding in a 50/50 mix of water and anti-freeze. Everything appeared to be working normally and I was inside the car watching the coolant temperatues on my guage. When the car warmed to 200 degrees, the service engine soon light lit up. I turned off the car and let it sit overnight.

This morning, I topped off the coolant and reservoir as well. It's taken 2 gallons of anti freeze and about 2.5 gallons of water. I started the car and everything sounded and looked perfect. The car was idling for about 20 minutes and right when the temp hit 210 degrees, the Service Engine Soon light litup again.

I shut off the car and there it sits.

Any ideas?

Z06pete

Air in the system, needs to be burped......

Nacho_ZR1

How do I do that? Is it as easy as raising the car on it's right side as described in Haibeck's article? I left the radiator cap off today when I started up the car so I could keep an eye on the coolant level. I did see bubbles and as the coolant would lower, I would keep filling it with water to top it off.

Do you think it could be a bad thermostat or is it just air in the system somewhere??

Goldcylon

Yes raise the car up and add as required

Demps

I would check the SES light myself.

As far as air removal:
Another technique I use is to loosen the small hose on top of the radiator (pass. side) and fill reservoir until water comes out hose.

The jacking technique has worked for me to get the air out.

Just changed out my thermostat and these worked.

Ted

Goldcylon

Agree it is unusal that the SES light came on so pull the code. IF you told me the low coolant light came on that would have not surprised me

Nacho_ZR1

I went outside earlier this evening and jacked the car on the right side. I checked the coolant level and it was full. I started the car and let it run for 5 minutes. The coolant level never dropped. I lowered the car and continued to watch the temp guage. The car warmed up to 225 degrees on the digital coolant guage and then the fans kicked in. I watched the temps slowly drop down to the low 200's. So far so good. All of a sudden, the SES light came back on. I shut the car off and called it a night. I also noticed that the analog needle on my temp guage never moved from it's 12 o'clock position. Not sure if this was because I was just idling the whole time or if its something to be concerned about as well.

-Sad in Dallas

xlr8nflorida

You need to make sure that you have enough coolant.

If you are not sure, I'd start over again. It appears you put plenty in, just need to watch out for air pockets.

If you run the engine low on coolant (IE AIR POCKETS) , sometimes the temp gauge won't work because coolant is not flowing past the temperature gauge. You need to feel the left cam cover and see if you can briefly touch it or if it is getting really hot.

It should not run for more then 3 minutes in that condition:

http://www.zr1specialist.com/HAT%20W...%20Coolant.pdf

The analog gauge should be showing temp as well.

Nacho_ZR1

I hope I haven't done any damage to my car. I went outside and the cam cover feels hot, but it wasn't anything too extreme. Of course, I've had the car turned off for about a half hour now.

If I hook it up to a code reader, will it show anything?

xlr8nflorida

I'm sure you are fine, I'm just not sure what it means to have one gauge work and not the other but I do know what marc wrote in the article. The Left side (driver side) cam cover will be warm on a cold start, after 3 minutes you should be able to touch it without it being super hot. If it's super hot, there is a problem and you need to shut down.

Of course the cam cover is going be hot now after running it for 20 mins so don't fret that.

I'd email Marc and he will be able to give you the best advice.

mhaibeck@sbcglobal.net

He usually answers about 3am in the morning so maybe you will have an answer in the morning.

Good Luck - Hang in there!

8388

Doubt it. Sometimes the answer is to just let gravity do the work of filling up the empty pockets. Once you have it under control and can see fluid moving (meaning you got rid of the air pockets) you can use a technique called cramming to get the most antifreeze into the system. Simply rev the engine lightly while adding antifreeze.

Also, make sure the reservoir is clean, as any junk left in it can get sucked back into the radiator.

JetJock

The service manual says that as long as the engine did not reach 260 degrees, you are okay. When you get home, check the oil level and check the analog gauges. Note the positions. I agree that the analog gauge should read but could have been disconnected. I'm thinking that the SES light is coming on for another reason as the manual does not discuss the SES light at all. The chapter on cooling is concerned with the hot light coming on and overtemp conditions. You know that the thermostat works and that the fans will come on which is very good. Like I told you, the engine will let you know before an overtemp occurs. Be patient, young whippersnapper or I'll sic Sampson on you. It's all good.

xlr8nflorida

Coolant should be 50% distilled water / 50% Coolant

If you run 100% water, you will have corrosion, lack of lubrication for waterpump etc.

You never want to run on 100% coolant as you will have overheating issues among other problems.

Make sure you put in, what you took out?

Good Luck, let us know how you make out.

I'd disconnect the battery and get rid of the SES light and see if it comes back.

Nacho_ZR1

Hehe yea I am hoping Santa brings me some patience for Xmas
The Z will be sitting safely in the garage until my plane touches back down Thursday night.

not sure how we could have disconnected the analog guage? Ah well. I'll wait for you to lay your healing hands on her this weekend

Paul Workman

Congratz on your Z! You're obviously very enthusiastic about it, and that is a good thing.

However, may I suggest you channel some of that energy toward getting a scanner and an FSM - two of THEE most useful tools you could have for troubleshooting and maintaining these toys. And, another thing: These LT5s are not just some SBC that you can dig into and thrash about. Not that they are especially fussy, but there are over 65 different electrical connections on this motor, and a combo of a dozen or so vacuum connections devices too. Point being, there is ample opportunity to phoch something else up when working on something entirely different. And, it sure helps to be able to put a scanner on it and have it tell you something like - "Hey, stupid! You forgot to reconnect the MAT sensor!" (Ya have to pay extra for a scanner with personality like that -- JK )

As much as you obviously like to fuss with and get to know your new toy, getting a scanner and definitely the FSM will serve you well, my friend. (In the voice of Yoda) "Do it NOT and grave will be your consequences!"

Enjoy!

P.

phrogs

There is no SES light for coolant guys sorry but there isnt one.

Your SES light is for something else.

Also if you had coolant problems runing it for more than 3 minutes and you have already done the damage.

your coolant didn't climb high enough for me to think you need to burp it. Its working fine I just changed out my water pump and needed to burp mine I knew it had an air pocket becuase once the motor got hot enough after about 2 min it really got hot and fast so I had to shut it down.
waited over night and she burped her self.

Good way to know if its running right is take off the radiator cap, start it up and once the thermostat opens up you will get coolant shooting into the coolant tank if nothing is comming into it then you have an air bubble and the water pump isnt pumping.

If you get a low coolant light that is strictly from the coolant in the coolant tank the black one thats where that sensor is. When that gets low you get the low coolant light. If your motor was bone dry no light will display if the tank is full and you temp will not be moving because that sensor is located in the thermostat housing and that is how you can overheat one of these very fast like I said don't run it more than 3 min if you dont see coolant moving in the coolant tank.

If you jacked it up and ran it Im more than sure you have burped it if it even needed it they do not always need it.

You need to pull that code for the SES light get a paper clip and check it out see what it is.

Aurora40

It takes about 45 seconds tops with a paperclip to retrieve the codes being set. There is absolutely no point in speculating about what is wrong or what your coolant change did if you don't pull the code from the car.

http://www.aldlcable.com/ <-- scroll down to "The Quick Paperclip Test"

EvanZR1

FYI, when we were filling it with coolant, I did feel both cam covers and they were about the same, with neither being too hot to touch.

JetJock

He lives in Cedar Hills, Tx and works in San Jose, Ca. It'll be Friday before we can take a look at the codes and the temp gauge. Plus, Carlos probably doesn't trust himself with a paper clip let alone a scanner. These engines were built tough. I was busy loading equipment into the Tahoe but I was watching Evan and John and looking underneath the engine to check for leaks. Everything looked normal until the SES light came on. We know that the digital temp gauge works. I am not too concerned about the analog temp gauge as it is not the primary here. The engine starts and runs smooth which it has not in a long time and sounds good. We got four days to look at the manuals. I have the stuff to check for codes and we will do that Friday. CHILL, Nacho Z!

ZRWHAT

Nacho,

Are you sure the light you are seeing isn't a service ride control light which will lite up and display after 3 startups and car not moved during that time?

As other had suggested, have you topped off the lower coolant resouvoir, the one that sits below the right hand headlight assembly.

Gibby