Car does not start. Had oil in throttle body and air intake boot.

I have checked all hoses to see if there is a loss of a vacuum but they all seem fine.
I have put in a new air filter and oil filter and the problem still persists.
I checked all electrical connections - cleaning them of any debris and also cleaned up my ground connections but again nothing has changed.

Today I took out the throttle body in an effort to clean any potential deposits.
The throttle body looked relatively clean however the part on top of the throttle body (is this called the intake manifold?) had a fair bit of oil in it - which had bled down into the sensor located on the front of the throttle body. It also seems that this oily deposit is going into the intake boot and down the air intake hose from the air filter.
After having attempted to clean all of this up I reassembled everything as was and unfortunately it now seems even worse.
There is a hose coming off the right hand side of the intake boot that goes to the engine and this seems to have a big build up of oil and nasty deposits in too.

When disassembling the throttle body (and what I have assumed to be the intake manifold) it struck me that there didn't seem to be any gaskets on the components- just one from the air boot. Not much to do about it, it is an infinite problem

Sounds like timing belt

low compression or spark plugs need to be changed.

A lot of cars, trucks, SUV's, Toyota 4x4's will not start , until COMPLETELY assembled. I have left off just the last air boot between the filter & intake throttle body, & NOTHING. Then sprayed a touch of "starting fluid" & Varooom. It came to life. I checked fuel rail, it checked out, still nothing. I gort angry, had picked up the vehicle cheap, for a quick "flip" for some extra money while the wife was hospitalized. I didn't have any more time to fool with it. Put the boot back on between the filter & throttle body. Put a For Sale sign on it. Turned the key....to turn the whell to roll it down into the yard, & it fired & ran. After scratching my head a while, I took the boot off, NOTHING ELSE, no start.sure it is completely assembled.

Have you had the trouble codes scanned yet? if this car has a manual throttle body, suspect vacum leak somewhere of a bad iac valve.

If this car has an electronic throttle body, suspect the throttle body itself OR sometimes ive seen the rubber boot in front or behind the throttle body rip and cause drivability issues.

Im assuming that there are ni mosfires or any other codes present. Its pretty hard to diagnose a problem like this over the internet but ill help you any way i can.


Keep putting in oil unless you have a pouring leak. Those northstar engines tend to both burn oil as well as leak it from the engines case halves. The only way to reseal the case halves of the engine is to remove it. Its honestly about a 20 hour job so like i said, right now it sounds like adding oil is going to be the way to go.

The Idle Air Control valve is located on the throttle body. If you follow the intake tube from your air filter all the way back to the intake manifold, where the intake tube connects to is the throttle body. Remove the intake tubing and you can see the throttle body.

There are two sensors on the throttle body and a vacuum line. You'll see two harnesses going to the throttle body, one is the IAC.

However, a quick diagnostic check can be done without touching the throttle body to confirm your problem. If the car has a normal idle when initially started but then rises to a higher idle and stays there BUT then if you were to shut the car off and restart it and it comes back to normal that is the Throttle Position Sensor (TPS). This is also located on the throttle body (the other sensor to the IAC). If it is the IAC it will be high and maybe fluctuate a bit.

If its a 99 4 cyl 2.4 ltr it should have a timing chain. Check your PCV (positive Crankcase Ventilation) Valve. it should rattle when you shake it. sometimes you can clean it with carb cleaner. but for what they cost, just go buy a new one. When they plug up it doesn't let your crankcase breathe and you will start getting oil in your throttle body or carb. Gas engines don't like to run on oil for the combustion process.4 cyl engines dont have a pcv valve just the v6 motor...

Pull the large hose off of the throttle body that come from the air filter and clean all the carbon out of there if is real bad pull the throttle body so you can get to both sides and clean use carb cleaner

change fule filter if nothing changes do fule pressure test

I believe it's your Throttle Position Sensor.