hithesh

I was driving my i30 to work today and I felt the car hesitate a bit (like the engine missing a heartbeat and stuttering).

I hooked up the ODB....the coolant temp was high (119 C).
It's been hot (102 F) in Northern California for the past few days and I have been running the AC at 50% speed (2 fans).
I turned off the AC and the coolant temp began to drop. The dial on the dash board was back to normal. On the ODB, the coolant temp was 101 C.
What should be typical coolant temp?

The CEL light came up. I ran the diagnostics on the ODB and it was something related to power train. Accidentally cleared the codes and now I can't remember the exact code.

I can still feel the Engine stuttering. Any help/suggestions?
Is this related to transmission?

Car details:
2000 i30t
200800K miles
No issues recently...in the past year or so.

maxiiiboy

119'C is 246.2'F.
That's high. And both of your fans are running.
Normally, coolant temperature should be below ~ 203' F, occasionally rising to perhaps 215'F. So you are quite high.
Check your coolant level. The thermostat is an obvious next step, but I would make sure that everything else is OK before trying to replace it.

hithesh

Around afternoon I did check the coolant level and the tank was empty. I did see some coolant on the base of the tank.
Filled the coolant, started driving back home. Coolant temp started to go up again but did not cross 97 C (206 C). I stopped mid way, checked coolant tank. All the coolant was still there. So no leaks. started back...after a few mins the coolant temp dropped and by the time I reached home it was 95 C (203 F). Checked the coolant tank after reaching home, it looked empty....probably it was all sucked into the radiator.
It took a while for the new coolant act. Is this normal?
Stuttering was still there, I read the fault codes. It's P0304. Maybe ignition coil.
Could the coolant over temp have caused this failure?

maxiiiboy

Ignore the P0304 until you fix your coolant problem.
Re. your coolant, you need to address the following three issues:

1. You can't just add coolant; you have to bleed/burp the cooling system,
2. Identify and fix the source of the leak (otherwise, the problem will happen again),
3. Confirm that your engine has not been damaged by running with low/no coolant.

Re. #1: See the drain/fill procedure on pages MA-12 to MA-15 of the FSM. (To download the FSM, use the link in my signature below). I recommend using Nissan antifreeze. For a quick and dirty re-fill, position the car so that the radiator is up, then open the radiator cap, engage the heater, start the engine, and keep adding coolant until overflow.
Re. #2: Be aware that leaks may occur in the following places: radiator, radiator hoses, water pump, head gasket.
Re. #3: Hope that your head gasket is still OK.
Good luck!

hithesh

I added coolant directly into the radiator before reading your reply.


1. I did the quick and dirty coolant burp. There was a little excess coolant...maybe half a cup of coolant in the funnel above the radiator level.


2. I don't see any obvious leaks


3. How do I find out if the head gasket is bad?








Here's what happened after I added coolant to radiator:
Day1: all good...drove for about 50miles
Day2: When I stopped at traffic light...the engine stuttered (hiccup) a bit
Day3: Did the the coolant burp and did a test drive. The stuttering decreased by half.
Day4: Repeated the coolant burp again ...the stuttering decreased a little more. On the way, I saw a autoshop and tried to get him to check. He said he was closed but mentioned the coolant might be leaking into the engine...and engine was burning coolant. Which only means bad things are waiting to happen?

Stuttering happens only when the car is not moving like when I am at a traffic light.

How would coolant leak into the engine. Head Gasket?

maxiiiboy

When the Head Gasket is bad, coolant will be leaking into your engine causing: a) Coolant in oil, so oil will be milky-looking, and/or b) Misfiring.
The opposite may also happen: oil in coolant, making coolant dark/oily (less likely).
If your Head Gasket goes bad, it's bad news.
It's an expensive repair and most people on this forum would recommend that you just replace the engine (with a used one, from junkyard). It's easier and perhaps even cheaper. There are many threads on this subject, so just search.

hithesh

The coolant looks good. Just like new..no contamination.
I am gonna check the oil tomorrow. The dipstick didn't show any signs of milky looking oil.
Where do you check the oil?

When this thing happened....I might have driven the car with high coolant temperature for maybe 5mins/half mile.
I saw the temp gauge go high, checked ODB and immediately parked and turned off AC. This dropped the temp gauge back to its regular position.

If the coolant is leaking into the engine, the coolant level should drop. I haven't seen this yet.
Shouldn't the check engine light come-on. I don't get any faults when I scan.

ukmastermind

Is there any special way to burp the system on these engines? I know the 350z's have 2 air relief valves at the back of the engine. I always have a hard time getting all those bubbles out.

maxiiiboy

Yes, there are two relief valves but they are PITA to get to.
Raising the front of the car, and then running/filling through an open radiator works fine for most people.

hithesh

I changed the oil today. No creamy or gooey stuff. I'll attach a pic later.
I also did the chemical block test. It came out negative. Repeated it once more ...negative again.

Can I rule out head gasket damage?

wonder why the engine would stutter.

maxiiiboy

Based on your description, it looks like you are lucky, and the head gasket may be OK.
That's still leaves the original problem - why did the engine overheat??

Re. stuttering: It could be related to overheating, or you may have another problem - perhaps misfire?
You need to be proactive and keep checking your codes

hithesh

The engine overheat was because of no coolant. I was stupid and didn't check/refill coolant.

I've been checking for fauld codes on ODB every time i start the car. All good as of now.

I did order a ignition coil and a spark plug just in case.
Can you recommend a thermostat?

The coolant I refilled was peak coolant and not nissan.
Would air in coolant cause stuttering.

It only happens after 15-20mins of driving.

maxiiiboy

OK, but how come there was "no coolant" - how did it escape/disappear ?????
NO, all is not good now - you have not corrected the original problem.
Yes, OEM from a Nissan dealer or junkyard.
That might be ok, but you have to make sure that this coolant is compatible with our aluminum engine, our water pump, and seals/gaskets.
(Often, this is not easy, so using a "Nissan coolant" is the quickest/simplest way to go).
No, not directly. But it may cause overheating, which can lead to all kinds of problems.

That's a lot of questions. So good luck - you are on your own now.