SUCK! My 2001 Nissan frontier died.... headgasket? Gearheads...

So... cruising along, to go pickup the chick and go for a ride.

Cruise control, 75mph, flat fwy. I look down, and notice the coolant temp rising fast, and i notice the oil pressure light is dimly lit (not HARD on). I go OH NO.... and put it in neutral (take any load off the motor and let it idle), and roll to the side of the road. I killed the motor before i let the temp leave the 'optimal range' bracket. (did not hit the H on the scale).

Called my pops, told him to bring some water and meet me (i had driven the car 7 miles from my house, had let it warm up, and then began to drive). I change the oil every 3K miles with Synthetic Castrol, and take good care of my cars.

The car exhibited NO signs of overheating, i put a quarter of a quart of water into the coolant overflow tank, let it sit for about 30 minutes, and tried to gdrive the car 500yds to the next offramp.

Started the car, Idles perfect (no noises, rock steady), no knocking or any other signs indicative of NO OIL PRESSURE.

I pulled out into traffic nice and slow, got about 400 yds before the temp spiked fast. Killed it again and waited for the tow truck.

The rapid coolant spike makes me think the thermostat stuck partially closed.

I have no clue about the oil pressure idiot light.

I have the nissan factory service manuals, and did a diagnostic check on both the oil pressure sender, and the gauge cluster itself to make sure i am not getting false readings. Unfortunately, they all say systems are A-OK.

The motor exhibits no signs of lack of oil pressure. I need to throw a mechanical gauge on it to verify.

I changed the oil when it got home (was due, and planned for today). There is some 'cottage cheese' or water vapor at the filller cap, but there was none present in the oil. (came out brown and solid, like always).

Started to do a compression check, and believe i have a crappy Harbor freight gauge (was reading 75-100 psi on all cylinders. WAY too low to be legitimate, and the motor runs perfect and still had plenty of power. ).

What are your thoughts. I could believe headgasket, but there should be more water in the oil, if it blew a HG. runs fine, no steam out the exhaust.

i need to do a thorough leak down test, but am scared to run the motor with an indicated low oil pressure.

Your thoughts? Its my daily driver.... i may have to dig out the autocross porsche to get me to school now.

 

Well you already did a compression test - thing to look for on that despite the low readings was consistancy. If they were all much of a muchness on a cold and hot idle then seems unlikely to be HG. 'Mayonaise' in the oil is a sign water is getting in there but it can form if u do frequent short trips.
I'd check the zorst pipe and plugs for any oil on them. If they're clean I'd remove the thermostat and see how the temps are. Was it losing water?

 

it was a little low on water.

2 cylinders showed up with 75lbs, when the rest were 100 or a tad over. crap gauge tho.

Plugs were clean.

keep on thinking, i appreciate it keith

The oil pressure thing scares the piss out of me. I need to put a mechanical or test gauge on the block to make sure it has SOME oil pressure before i spin it again

 

Fan belt slipping?

 

can you see coolant around the exhaust manifold?

on second thought drive your porsche for a few days and have your butler take it to the dealer.

 

at 75 mph, the air coming through the radiator is mostly from the vehicle speed, not from suction of the fan i would assume.

no belt slipping/noises. water pump feels fine, no abnormal play, etc.

 

Check your water reservoir for oil. Make sure you don't have any leaks. Ever replaced your hoses and thermostat? Also, on my Pathfinder, my oil pressure sending unit leaked. I replaced that for cheap. Just FYI. Were you low on oil?

Keep me updated, I know the VG33E motor fairly well.

 

VG33E indeed.

Wasnt low on oil. It doesnt leak oil or coolant. Coolant was a little low, but nothing extreme.

No i havent replaced hoses or t-stat on it yet.

I was gearing up for the 100k water pump and timing belt deal. I have 93k on the clock

didnt see any there.

Porsche is an old 914 that is not fun on the street. Slammed and gutted... no sound deadening. Short geared tranny isnt fun at highway speeds with almost zero back pressure exhaust

 

Did you check the coolant temp sensor in the head.Was it actually over heating(bubbling in the overflow resivior/) or did the gauge just say it was.The coolant temp sensor and oil pressure sensor may be on the same circuit.At 100 Psi per cylinder it would probably not even start,and two at 75 psi wont even fire.You need a minimum of 100 psi to even get it to run.Let me know chewy,I can come check it out if ya like.

 

This sounds silly, but check your exhaust "odor". If it smells sweet, you're burning coolant and you have a bad headgasket. Otherwise, I'd say intermittent frozen thermostat. The low oil press is confusing, though.

 

Yea that is the weird thing (oil Pressure) any probs with the battery or alt?Im figuring the oil light and overheating are related to an electrical prob.:-k:?:
Might be over thinking it,but from what you describe I am trying to put two and two together.The sensors in that car use a 5 volt reference signal.Do you have a check engine light on, and have you scanned it?

 

if u want i can send you a pdf for the fsm for the frontier. that will be your best bet. the coolant temp sensor for the dash, different from the one to the ecu on nissans, is cheap, but i forget the location of it. dont know how hard it is to get to. it is just a rtd you need to measure with a dmm. the specs are in the fsm. regardless, you need to check the thermostat.

pm me. i have a hookup for nissan parts. 25% off

 

Very cool. My uncle is a nissan manager guy in tenn, but i will hit you up when i need some parts.

I have the FSM for my 01 nissan in pdf, thats how i got the gauge and pressure sender diagnostics out of the way.

k, i need to check the T-sat and put it in some boiling water and watch it open.

ONLY the gauge told me it was over heating. It exhibited no signs of overheating. The overflow was just about dry tho, so i topped it off to midway between max and min.

Yeah... the thing runs bitchin danny, and there is no way it would be running with 2 down cylinders. (crappy HF gauge).

No check engine light, and i dont have an OBDII scanner

keep it coming guys! you guys rock.

Danny, do you have an Oil PSI gauge on a short hose i could borrow?

 

yes,and a scanner as well.I also have a good compression gauge.

 

I don't know a damn thing about the truck, but you definitely need a beer. There should be some left in Ricky's fridge...

Good luck homie.

 

"Stan's Sealant!":?:

 

Ok, off the top of my head, there are two water temp sensors. One is a single blade connector, and the other is a 2 pin connector. Usually they are red and purple colored connectors. The single blade connector is the one that goes to your gauge. So look around the motor for 2 sensors right next to each other on the hard coolant lines.

Per the FSM, the blade connector resistance to ground should be should be 50ish ohms at 212F. Measure from the blade to the block with yoru DMM. You can just turn your key on to get your 5V reference to turn on and measure. At ambient temp, which is what your water temp should be with the motor off, your resistance should be well over 200 ohms.

Regarding your oil pressure sending unit, they are entirely on separate circuits. I'm not sure what it could be. Check your oil pressure sending unit. It is right above the front diff, if you have one. It is a round gold unit threaded into the back of the block. I found the best way to get it off is with big ass round gripped vice grips. See if it is leaking oil. They are notorious for leaks.

 

Cool. I will check the single pin coolant temp sensor tomorrow.

the oil pressure sending unit is located on the back of the oil filter boss. Single connector. FSM says while off, the DMM set to continuity should be continous to ground, and not continous when running. (i didnt do the running check).

 

Also keep an eye on that filler cap, it may be safe to assume the load of the A/C and being a little low on water may have led to simple overheating. But the presence of that nasty gunky foam on the bottom of the Oil cap is a red flag. Any incipient water would burn of in the first ten minutes of operation, guess it's the season to buy a new car already since mines dead too.

 

Just do a leak down test without the engine running with the radiator cap off. If you see any bubbles comming up from the radiator, you know the head gasket is toast. Do you have a leak down gauge set? compressor?