Prophecy99

iTrader: (1)

i have these codes after driving in a storm yesterday

P0128 Thermostat Function (probable cause - low coolant level, faulty thermosat , ect circuit fault)
P0328 Knock Sensor Circuit High Input (probable cause - poor electrical connection, electrical interferance on circuit, engine mechanical conidtion, faulty KS)


I replaced the radiator (koyo) (accompanied w a flush) February 2015 - I havent closely checked the coolant levels since doing that, but had a full 60k tune up , plugs , belts, in june 2016

Any input guys? Are these two codes associated ? I noticed the moment it came on driving in a very strong rain storm, yesterday.
I know I am 1000 miles over an oil change interval, but oil level is fine, checked this am. I run premium fuel, and have a grounding kit. i am at 199k miles.

Prophecy99

iTrader: (1)

no one else replaced a knock sensor? or dealt with these codes? i found one thread on this and best post on the two codes was this

dwapenyi is the ultimate fix to just replace the knock sensor? i cant believe i haven't found any more info on these codes., it sucks throwing parts at it, as I am not sure what else to do, i havent discovered any org secrets on the 5.5 gen knock sensor.

i dont have pinging been running premium for years (except from the rattling noise from the serpentine idler pulley belt which can be mistaken for pinging)

car drives fine and smooth. just dirty oil

DennisMik

iTrader: (2)

The knock sensor code, P0328, likes to show up whenever you have something that makes the check engine light turn on. It is referred to as a ghost code because 99.99% of the time it goes away when you fix the other problem(s).

P0128 is when the engine coolant does not reach operating temperature when the engine has been running long enough to have reached operating temperature. The most logical causes are a thermostat that is stuck open of a bad ECTS. Low coolant level - I don't think so.

Get a OBD code reader that can read live data and see what the engine coolant temperature that is being reported by the ECTS is. Normal operating temperature fluctuates between 180º and 203º F. This will tell you what kind of reading the ECU is getting, but it won't indicate the problem part.

Prophecy99

iTrader: (1)

Dennismik - do you take donations? thank you Dennis, i had a feeling the knock code was a ghost code my self considering my maintenance, choice of premium fuel, and twc3 additive, and mostly undetectable symptoms , the car is driving completely fine ( i notice many subtle things , and there isn't much to be felt on this one)
and the coolant yea I am not leaking, and replaced radiator 19 months ago (top seals/edges were starting to seep)

and are you suggesting either replace ECTS or Thermostat based on the live OBD code reader findings?

Thanks again!

DennisMik

iTrader: (2)

Yes. However, I do have to reverse my position about the OBD live reading. It can tell you if the ECTS is bad under certain conditions.

Based on ease of diagnosing, I would check out the ECTS first. You don't even have to remove it from the car.

When the car has been running for a while, long enough to have reached operating temperature, turn on the heater. Is it blowing hot air like it should? If yes, then the coolant temperature is probably what it should be. At this point, what does the OBD live reading report? If the reported temperature is below the ambient air temperature, the ECTS is bad.

The ECTS can also be tested with an ohmmeter and without having run the engine. Remove the wire harness connector and do a resistance reading between the 2 pins on the ECTS. On a cold engine at 68º F, the resistance reading should be approx 2.5 ohms. At 194º F (operating temperature) the reading should less than 1 ohm, approx .25. As the resistance reading goes higher (more ohms), the ECTS is reporting colder temperature. For example, 32º (freezing) would give a reading of approx 6 ohms. dropping to 0º would give a reading of 7 to 8 ohms.

If it were the thermostat stuck open, fact is that the coolant temperature would rise slowly, but not to operating temperature. But testing the ECTS should tell you what part has the problem.

Prophecy99

iTrader: (1)

I cannot thank you enough man. I will check the hot air after running engine to normal operating temps today.

If i tell a shop to replace the ECTS (seems cheap part and easy enough) and reset codes, do you think that is a good blind bet to start with?

DennisMik

iTrader: (2)

As parts go, the ECTS isn't a very expensive part. Local auto store price is in the $20 to $30 range. You can do it yourself, it is fairly accessible. You don't even have to drain the anti-freeze. When the engine is cold, just unscrew the old one and pop the new one in real quick. You will lose very little coolant. Five minutes and you are done.

Only caution is you do not want to play superman when you tighten the new one. The engine is aluminum and you can strip it playing superman. Pull on the wrench with maybe 10 pounds of force and you will be good.

Prophecy99

iTrader: (1)

Dennis, I had a shop replace the ECTS for that code and reset the SES light, it has been off since. Can't thank you enough.!

Kevinsnelgrove

Here's the skinny: Codes thrown: P0328 (Camshaft Position Sensor), P0340 (Knock Sensor) Symptoms: occasion hard start, random shut off while driving & hard re-start. Replaced Camshaft sensors- Bank 1,2. Car no longer shuts off. Occasional Hard start remains. Car performs good, NO knocks, pings, stall, etc. 0328 cleared, but 0340 remains. Assuming knock sensor code is "Ghost Code" what could be setting it off that also causes hard start. Only using midgrade/high grade fuel.

Please help! I know someone out there in Maxima land had this issue!

Prophecy99

iTrader: (1)

hard hot starts are dirty throttle plate , i dk about cold starts, search around a bit more... and might i suggest replacing all 3 sensors two cams and one shaft sensor

Robert Baker

Knock sensors detect vibration. Your idler puller could be aggravating the knock sensor from increased vibrations through the block. I don't see how the two codes could be related unless a ground wire came off that's on the same circuit as both.

Prophecy99

iTrader: (1)

thats a nice stretch, but not even close, read enitre thread, codes resolved, and the association between the codes is explained above by the expert DennisMik

Prophecy99

iTrader: (1)

P0128 Code came back about 11 months later after replacing the ECTS, Dennis, should I now replace the Thermostat ?? Car is currently at shop, prompt reply greatly appreciated.

DennisMik

iTrader: (2)

You cannot automatically say that the thermostat is bad, just like you cannot say that the ECTS is good. Eleven months ago the problem turned out to be the ECTS.

But that was 11 months ago. Today is a brand new ball game. There is no guarantee that the ECTS you installed 11 months ago is still good. It has to be tested to see if it is good or bad.

Since the thermostat is probably the original one, being 18 years later, it has a good possibility of being bad.

But I can't guarantee that either part is good or bad. Sorry.

Prophecy99

iTrader: (1)

hey man! i greatly appreciate this info, i mean based on what u said its one of 2 things, and i will go with logic on that the ECTS i replaced (at a shop not me) is logically more intact and performing that a original thermostat that is possibly 15 years old !

a thermostat is relatively the same difficulty ( at a mechanic shop) than the ECTS correct?

Prophecy99

iTrader: (1)

by the way the shop is clearing the codes, and I go back thurs if my light is still off to do emissions, fingers crossed....

Prophecy99

iTrader: (1)

EVAP came back alone... i will have the shop smoke test the evap system and see whats good, then take plan of action from there.... maybe a bone yard visit.....

this car is too old for a new $250 EVAP canister and valve , for something that dosen't effect the operability of the car itself.... sighhh

the 2nd attempt at the caulking didnt work like the first time so either original caulking area is FUBAR , or theres a new leak somewhere.....

Tarzan

Is it possible to re-fill the evap canister? I know pharmacies can sell activated charcoal. Evap is a scam, just like cats are. For how long are we going to allow industry crooks to scam us of hard earned money, is beyond me.