Most responsive S5 cloolant gauge ever? The vert's endless problems.

[Max777]

Ok, so just how FAR into the "oh shit" zone does the S5 coolant gauge need to move in order to declare an engine a total loss? Is ANY movement toward the top bad, or does it have to be way up there?

I have read a ton of negative things about S5 coolant gauges on out cars, and Believed that if it moves... you are fucked... intill tohight that is!

My car, for $1000, came with a ton of problems.

The first, is about 90~95 psi of compression, and really wierd starting....

The clutch pedal is TOTALLY out of adjustment, far enough to make me consider a worn out clutch, and maybe a damaged arm? The car idles funny, it goes up to 2000RPM, and warms up... then falls to 1500 and bounces around there, going "Wraam-Brrrp-wramm-brrrrp-wraaaam-burrp" Also, the throttle cable is shot, the rear brakes started to grind after I left the hand brake on overnight... The engine was running low on oil, so I filled it up... then I noticed the FRAM, and went right back in to get a purolator and some 10W-40 Penzoil. Anyway, today, my coolant buzzer went off, and I drove carefully, and went straight to a gas station, turned the car off, and filled up the coolant-overflow bottle with a $10 bottle of peak coolant. The car did not want to start back up. I sat there for a while, and eventually it started.
I dove around a bit more, and noticed the gauge was a TINY bit higher on the scale then I remember... Then I pulled over, engine running, and called a friend.. he didnt pick up, so I decided to go home. Then I noticed the coolant gauge even higher! I was like, OH SHIT! I parked the car ASAP and turned the engine off. IT sounded like it was bubbling like mad, and coolant was spilling out of the little spout in the overflow tank cap. I called annother friend, and we towed it to his house nearby. I went back to the car 2hrs later, and checked the coolant again. The overflow bottle wasnt full anymore!
I filled it up again, and then mamaged to start the car... the gauge did not take long to show "1/2" AT ALL! I drove it home really quick, but was careful to not go over 3K rpm's, and parked it. The gauge read 1/2 still.

With a 20 year old car you get for $1000, stuff is pretty much expected to happen, but still, damn, why all at the same time? (body, brakes/susp. engine trouble?

I'm about ready to order a buch of block off plates, and go to town on the engine, taking out as much crap as I can to still have i be livable on the street. The car's problems have me going :leaving: right now.

[RETed]

The stock gauge isn't that accurate, so it's hard to give you a definite answer on this.
Seriously, an aftermarket water temp gauge can be had for cheap (i.e. VDO / Autometer), and it gives you a better idea of how hot everything is.

I'm am going to buck the trend and say it's not so much how hot it gets, but for how long @ what temps it was sitting at.
A temporary spike to "H" does not automatically mean your engine is dead.
I've done it, so I'm proof of this.

The LOW COOLANT warning light + buzzer is a very good indicator of a possible cooling system failure.

Your situation could be as simple as a coolant leak somewhere.
Cross your fingers it's not leaking internally on the engine.
Looks for signs of white crusty stuff in and around the cooling system connections.
This include:
Radiator hoses
Heater hoses (pay particular atttention to the ones going in and out of the firewall, and snaking under the oil filter)
Thermostat cover
Water pump
Water pump housing
Radiator
Radiator cap(s)
TB -> rear iron @)$%&$%)& hose

If your nose is sensitive enough, you can smell the coolant in the engine bay.


-Ted

[classicauto]

Well, couple ways to go at this.

For me, I'd keep driving it until the problem surfaces more definetvely. Check it over for obvious leaks before doing so and make sure the system is full and has no air in it and it wouldn't hurt to peek at the rad's front surface and make sure its not chalk full of gunk/grime.

Another relatively good test is to start the car when its STONE cold, and check the overflow bottle for coolant puking out. If its not pouring out of there, you're OK. But make sure to test when the car is COLD.

[Max777]

Well, drove it to school today, it warmed up relatively fast to normal temp.

My car also has what you call a surge. One of the guys I met at my friends house the other day, when he was doing a 5 lug swap on his 240, said that the surge could be caused by low coolant, and the previous owner had to ghetto rig it because of the coolant buzzer was going off... and I think he also mentioned the leak. The thing is, I drove it 170 miles home, and it didnt overheat, the gauge stayed at the same place the whole time.... the car exibits hard starting at times, both hot and cold, and that surge, and the clutch I think is going out...

but other than that, the thing drives pretty damn well, so is that a sign of a good thing?

I didnt go out to luch today because I didnt want to fuck up the car... driving it home at 3:00 and will post if I get any problems. I'm thinking I want to tear into it this weekend, seeing how my thermostat and master cylinder will be here by then.

[classicauto]

Surge? What do you mean?

[RETed]

When the engine is cold...
Open the rad cap...
Is it full?


-Ted

[djmtsu]

Fill it with coolant (to the top) leave the cap off and have someone crank it over. See if it starts to bubble a spit out when it fires up. Now, the level may go down if the coolant is low, so be ready to top it back off so you can determine if it is doing this.

How old is the thermostat? Is it sticking?

[Max777]

I dunno how old the thermostat is... The new one just came in, going to pick it up tomorrow. I ordered the OEM one, not the Stant, just as the evil forum once taught me. The thing is, after the coolant buzzer went off, I went straight to a gas station, and filled the overflow bottle. Then, the car got hot, I had a friend give me a tow home, and the car sat for 2 hrs. When I opened the rad cap, the fluid wasnt full, so I filled it up untill it spilled out (a bit careless with the funnel, lol) and I noticed that the overflow bottle was not full again. I filled it up, and drove the car home. Today, morning, I looked at the coolant in the overflow, and it was still full, but not clear, more like a brown color. That shit is getting flushed friday! Anyway, I got back from school, and it was still full... so I dunno if it's a leak or not.

Right now, I have a gallon of Mercedes undiluted coolant (good for aluminum engines because it's specially designed for MB cars) and 2 gallons of Distilled water. I'm gonna go order some hoses, and pick up that thermostat tomorrow, then proceed to rip into the engine bay....

[Max777]

Surge? What do you mean?

One of the guys at my friends called it a surge... it idles up, then down, up then down up then down, when it's warming up it idles at 2500 instead of 3000RPM....

[josh18_2k]

surging happens on cars where the idle is cointrolled by the temp sensor. when a pocket of air hits the sensor, the idle changes.
FC idle is controlled by a thermowax, so it maybe be a different problem. well s4's are anyway.. (does s5 use a thermowax?)
regardless, the boiling over should not be happening ever. make sure you completely fill the cooling system with the car cold, then start it with the cap off. keep it running until the thermostat opens. you'll know because the water will rise and start coming out of the radiator. then put the cap on, and fill the overflow bottle. at this point everything should be full of water.
run it for a while, let it cool down, and check the radiator level. if its not full you have issues.
in my experiance, boiling over is often caused by a leaky seal in the combustion chamber. the heat from combustion will seep through the seal and boil the water. lets hope thats not whats going on.

[FerociousP]

One of the guys at my friends called it a surge... it idles up, then down, up then down up then down, when it's warming up it idles at 2500 instead of 3000RPM....

adjust your tps...

the low coolant light and buzzer comes from the sensor in the top of the radiator, just filling up the bottle won't fix it... fill it up and leave the cap off, and see if it comes out with force, if it does you have problems (coolant seals). to burp it, you can take the small coolant line off the back of the throttle body going to the thermowax as it is a high point, as well as if you have the stock radiator use the burp screw on the side of the radiator where the upper hose connects...

[Max777]

Ok... I was looking around on atkins rotary, and the thermowax solid replacement is only $7.95... should I just get that and put it in just in case? I know they like to crap out...

[Max777]

So I did the whole "leve the radiator cap off, and start the engine thing today... Coolant did "burp" out at first, but it wasnt too bad, probably just an air bubble... I filled it up, and it went in, filled it up again, and it just kinda stayed there, moving up and down just a little, but no crazy air bubbles or anything like that. I think I'm good as far as the coolant seals, but I'm replacing the hoses, T-stat, and coolant ASAP, that s**t looked nasty.

Thanks for the help guys!

[FerociousP]

when the thermowax goes bad, you have idle start-up problems as it moves a cam on the throttle based on temp.... as far as the coolant side goes, the coolant just flows through it and as the car warms up, so does the thermowax... you wouldn't overheat because of a bad thermowax

it is good that it doesn't spray out though

[Max777]

So, should I get that thing from Atkins? Or should I just shim it?

[Phoenix7]

has it overheated since you got rid of the air bubbles via the FSM method (leave cap off and turn the car on)?

[Max777]

Nope! I drove it about 5 miles, and then went home, no issues.


Just as a note: The car did NOT "over" heat when this initially happened. The gauge was up there, but it wasnt all the way up, or "pegged" in the H... I try to pay attenntion to my car. Also, I havent driven it further because as I said, the coolant is crap, and I am flushing it tomorrow.

[Phoenix7]

sweet. Good luck.

[FerociousP]

what thing from atkins? shim it? are we talking about the same thing?

[Max777]

Umm, well I heard "Thermowax" and that made me think of the oil pellet thing in the center of the ecentric shaft that fails and causes low oil pressure.... I am confused as well.

[RETed]

There are many "thermowax" devices on the engine...

There is the front eccentric thermowax pellet which allows oil to flow through the eccentric shaft (and rotors).
There's the thermowax on the throttle body which controls the cold-start fast idle.
There's the thermowax pellet in the oil cooler which allows oil to bypass the oil cooler core.

When talking about COOLANT, there's only one thermowax on the throttle body.


-Ted

[Max777]

Thanks Ted! now I got it! I had no clue about the one on the TB!

[Max777]

Update on the thread: I got replacement hoses, thermostat, and radiator cap, as well as really good Mercedes coolant, it's all ready to put in, except for the fact that I cant quite get to the block drain plug to drain the rest of the coolant out... I think I will need to take out the AC compressor to make the job easier.

My radiator had quite a bit of CRAP logged in there. I sprayed a TON of degreaser, follwed by garden hose, an then power washer. The radiator is pretty much see through right now.

[classicauto]

I cant quite get to the block drain plug to drain the rest of the coolant out... I think I will need to take out the AC compressor to make the job easier.

Look at your drivers side engine mount where it bolts to the block. Notice the 3 studs/nuts? Notice the long hex "nut"? Undo the hex nut and you'll drain the coolant out of the block. IIRC that drain is lower then the one behind the P/S pump bracket anyways.

My radiator had quite a bit of CRAP logged in there. I sprayed a TON of degreaser, follwed by garden hose, an then power washer. The radiator is pretty much see through right now.

Nice, thats always good ;)

[Max777]

Found it after I took the AC compressor out! But thanks anyway!

[FRFC3S]

My surging idle was solved after a readjustment of the TPS. It may not be your case but I'll throw it out there. It's easy enough (especially on an N/A, no TMIC) to get at and takes 5 minutes to do. Rule it out as the problem if anything.

[Max777]

Well, where can I get one of those meter tester things at? I dont have one, and dont have any $$$ for one atm. Maybe I'll borrow one or something.

[djmtsu]

Its called a multimeter.

You can get one at Radio Shack, or wherever.

Or you can buy one from--> http://www.banzai-racing.com/

Go under products, FC, TPS tester.

[Phoenix7]

You can build your own LED tester also. I'll try and find the info and make a thread for future reference.

A multi-meter can be found cheap (less than 20 bux) and can go as high as $100+

[micah]

Its called a multimeter.

You can get one at Radio Shack, or wherever.

Or you can buy one from--> http://www.banzai-racing.com/

Go under products, FC, TPS tester.

If you get one from radio shack or what not, get the analog cheap-o type.. a cheap digital multimeter will NOT give you the quick reaction you'll need to check the TPS correctly. The TPS is a potentiometer.. finding opens in the "sweep" will be easier with an analog meter. They are also cheaper.. I think I got mine for 3 bucks. hehe.

Also.. Careful with the pressure washer on the radiator. You can often times do more damage than you think. Same goes for the rest of your engine bay.. Pressure washers tend to introduce more problems.

[Phoenix7]

http://rotarycarclub.com/showthread.php?p=14150#post14150

I'm adding more to it as I can so stay tuned. :lol: no pun intended.

So far I've added the ECU part and I'm about to add the ECU codes. I'll get the TPS section in there soon, I'm sure you haven't built it but I'm trying to compile the data right now.

[Max777]

[QUOTE=micah;14147
Also.. Careful with the pressure washer on the radiator. You can often times do more damage than you think. Same goes for the rest of your engine bay.. Pressure washers tend to introduce more problems.[/QUOTE]

You really think that a radiator will break?

FYI: I did not use an industrial strength ( IE: heated water and a SHIT load of pressure) pressure washer. I used a lower power cold water one that you find at those DIY car washes. (The ones where you pop coins in and wash your car.)

I DID use a VERY powerful one at a shop once, to wash a car, and I can see how THAT sucker can do some damage!


PS: My rad is coming out in exchange for a nice Koyo one sometime soon, so dont worry!