This is going to get confusing
08-30-2009, 09:49 AM
#1
Registered User
Thread Starter
Join Date: Aug 2009
Posts: 7
This is going to get confusing
Alright let me start with my introduction. Sup i'm new here, I own a 1990 300zx TT that ran pretty good with no promblems until now. The car was rebuild before I bought it and now the engine ran strong until i came to a few promblems.
It all started with the engine's idle dropping at times. I started to hear a few sounds on the engine the engine ran strong for 2 months until one night i was parked. I started the car then it started to make a few more sounds,till i got out of my car and pop the hood. I reved it from the throttle wire then car shuts off after the excessive sound. It sounded like knocking sounds. Ok i think its a bad lifter for many months i have not done anything just guessing my way through it. I brought it to a shop, they told me my timing belt jump time and stretched or something like that and there is no compression on the motor. They wanted to pull the motor to see if it damage any valves,but i didnt have the money so i took the car back home.
Now I've finally got some help from three 300zx enthiuast in my home town with three different opinions about my car. One of them came over and told me that i might have spun a rod bearing, another told me that it could be just a PTU recall on your 300zx and finally someone just told me to get an engine.
It all started with the engine's idle dropping at times. I started to hear a few sounds on the engine the engine ran strong for 2 months until one night i was parked. I started the car then it started to make a few more sounds,till i got out of my car and pop the hood. I reved it from the throttle wire then car shuts off after the excessive sound. It sounded like knocking sounds. Ok i think its a bad lifter for many months i have not done anything just guessing my way through it. I brought it to a shop, they told me my timing belt jump time and stretched or something like that and there is no compression on the motor. They wanted to pull the motor to see if it damage any valves,but i didnt have the money so i took the car back home.
Now I've finally got some help from three 300zx enthiuast in my home town with three different opinions about my car. One of them came over and told me that i might have spun a rod bearing, another told me that it could be just a PTU recall on your 300zx and finally someone just told me to get an engine.
08-30-2009, 11:23 AM
#3
Encyclopedic Knowledge
Join Date: Aug 2005
Location: Naperville, IL
Posts: 3,316
Dude, all of those things are easy to check had you searched for any of your answers first.
To address timing issues, get a timing light and check the ignition timing. If the timing belt jumped a tooth, the timing light should be erratic (I once installed the belt one tooth off and it was clear when that was the result). If the light is steady, the timing belt is fine. (While you're at it, make sure ignition is set to 15deg BTDC.)
To address compression... do a compression test. Should be 128-171 psi with no greater than 14 psi difference between the maximum and minimum. Do a leakdown test to check your valves.
To address the rod knock, consider your oil pressure and when the sound occurs. If your oil pressure has been low, that could be a side affect of bad bearings. If the knocking sound goes away when you're revving the engine (or any time there is a load on the engine), it's probably rod knock. Rod knock occurs at constant RPM's and goes away under load.
And call 1-800-NISSAN-1 with your VIN in hand to check if your car received the PTU recall. Or just compare yours to this
If you have the pre-93 one, you never got the recall.
And by the way, all the tools needed to do compression and timing tests can be rented for free (after deposit) from Auto Zone, Pep Boys, etc.
To address timing issues, get a timing light and check the ignition timing. If the timing belt jumped a tooth, the timing light should be erratic (I once installed the belt one tooth off and it was clear when that was the result). If the light is steady, the timing belt is fine. (While you're at it, make sure ignition is set to 15deg BTDC.)
To address compression... do a compression test. Should be 128-171 psi with no greater than 14 psi difference between the maximum and minimum. Do a leakdown test to check your valves.
To address the rod knock, consider your oil pressure and when the sound occurs. If your oil pressure has been low, that could be a side affect of bad bearings. If the knocking sound goes away when you're revving the engine (or any time there is a load on the engine), it's probably rod knock. Rod knock occurs at constant RPM's and goes away under load.
And call 1-800-NISSAN-1 with your VIN in hand to check if your car received the PTU recall. Or just compare yours to this
If you have the pre-93 one, you never got the recall.
And by the way, all the tools needed to do compression and timing tests can be rented for free (after deposit) from Auto Zone, Pep Boys, etc.
08-31-2009, 10:46 AM
#4
Registered User
Thread Starter
Join Date: Aug 2009
Posts: 7
Dude, all of those things are easy to check had you searched for any of your answers first.
To address timing issues, get a timing light and check the ignition timing. If the timing belt jumped a tooth, the timing light should be erratic (I once installed the belt one tooth off and it was clear when that was the result). If the light is steady, the timing belt is fine. (While you're at it, make sure ignition is set to 15deg BTDC.)
To address compression... do a compression test. Should be 128-171 psi with no greater than 14 psi difference between the maximum and minimum. Do a leakdown test to check your valves.
To address the rod knock, consider your oil pressure and when the sound occurs. If your oil pressure has been low, that could be a side affect of bad bearings. If the knocking sound goes away when you're revving the engine (or any time there is a load on the engine), it's probably rod knock. Rod knock occurs at constant RPM's and goes away under load.
And call 1-800-NISSAN-1 with your VIN in hand to check if your car received the PTU recall. Or just compare yours to this
If you have the pre-93 one, you never got the recall.
And by the way, all the tools needed to do compression and timing tests can be rented for free (after deposit) from Auto Zone, Pep Boys, etc.
To address timing issues, get a timing light and check the ignition timing. If the timing belt jumped a tooth, the timing light should be erratic (I once installed the belt one tooth off and it was clear when that was the result). If the light is steady, the timing belt is fine. (While you're at it, make sure ignition is set to 15deg BTDC.)
To address compression... do a compression test. Should be 128-171 psi with no greater than 14 psi difference between the maximum and minimum. Do a leakdown test to check your valves.
To address the rod knock, consider your oil pressure and when the sound occurs. If your oil pressure has been low, that could be a side affect of bad bearings. If the knocking sound goes away when you're revving the engine (or any time there is a load on the engine), it's probably rod knock. Rod knock occurs at constant RPM's and goes away under load.
And call 1-800-NISSAN-1 with your VIN in hand to check if your car received the PTU recall. Or just compare yours to this
If you have the pre-93 one, you never got the recall.
And by the way, all the tools needed to do compression and timing tests can be rented for free (after deposit) from Auto Zone, Pep Boys, etc.
I am sorry but i am very lackey when it comes to mechanical stuff I am still learning as I go. Most things I haver ever done to my Z myself is an oil change, fuel filter, starter and my intake. As far as compression testing and timing testing i think thats far more advance for me. Its alot of work just to check my timing belt. I will have to take out the radiator,fan and all those stuff in the way of the valve cover. But you have any instructions on how to do all those diagnostics cuz i am thinking about doing it myself.
I also call Nissan for the recall thing. All they said was there are no Archives recall for my 1990 300ZX TT. Okay?? I saw my PTU its still the old one. So how am I going to fix this recall promblem for free? If they said there are no recalls for my year.
Last edited by vgz32john; 08-31-2009 at 06:23 PM.
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