'03 ultra, coolant loss, ticking, and ping?

[Rayzor32]

This is for my dads car, its a 03 park ave ultra with the 3800 supercharged motor. its got a couple problems. First its losing coolant somehow, i dont see any evidence of a leak (nothing on ground) I read this may be intake gaskets or something with an egr or plenum?? Second, sometimes on startup the engine will tick pretty loud (sorta sounds like tapping on a piece of plastic sound) it seems to happen when its cold but its intermittent. Third, when cruising on the thruway you can feel like i cant describe it but it feels like a slight jolting or dragging, i think it might be engine ping cos we just put regular in and the book says 91 octane, either that or something in the tranny but also today it wasnt idling smooth. Also the SES light comes on sometimes, I gotta get a code reader cos you cant jump the wires on obdII i think, i notice itll flash on whenever you gun the car.

[Blue Bowtie]

A prime suspect for inexplicable coolant loss is the intake manifold. Proper diagnosis can identify most leaks in the cooling system.

Regarding the cold startup noise, make sure the engine has the correct engine oil AND the correct filter. Oil of the proper viscosity is necessary for cold lubrication. An incorrect filter may cause inadequate oil flow and pressure on cold starts. HINT: If your oil filter is orange, it is an incorrect filter.

As for the other issues, you'll need to scan the PCM for DTCs to help determine the problem(s). The low octane fuel may be part of the problem, but the PCM is probably trying to tell you more.

[BNaylor]

It would help to post your mileage.

The PA Ultra has the L67 supercharged II 3800 engine and you should not run regular unleaded fuel but 91 octane or better premium unleaded fuel only!!!. You are most likely getting detonation which will cause knock retard (KR) which is sensed by the knock sensors and controlled by the PCM module. If the SES/CEL light is blinking it is a misfire condition detected.

Also, there is no UIM plenum in a L67 engine like the normally aspirated SII 3800. Nor does it suffer from the infamous EGR stovepipe problem. The supercharger is the upper intake manifold. Your coolant loss is either external or it could be the LIM gaskets (lower intake) or bad suppercharger coolant passage o-ring seals located between the supercharger and LIM.

[Rayzor32]

haha well try telling my dad he should use 91 octane , the mileage is 115k. It needs an oil change soon so ill make sure it gets the right oil, ill check the gaskets and do a scan, and im gonna change the supercharger oil also.

[BNaylor]

How old are the spark plugs and ignition wires? Air filter, fuel filter...basic tune up? Info below is for you and your Dad's edification.

L67 SII 3800 engines require 91 octane premium gas or better per the GM owner's manual. However, 87 may be used only in emergency situations for a short period of time. The primary concern on a L67 engine is knock retard (KR) due to the supercharger, especially in high boost conditions. If KR is detected the PCM will retard igniton timing degrading performance or fuel economy.

Here are some interesting facts:

For every 1 degree on a L67 SII 3800 you will lose approximately 2 - 3 horsepower.

For every degree of knock retard it takes .8 seconds recovery time.

"Once the PCM has retarded timing sufficiently to reduce knock below the currently detected peak level, a changeable parameter in the PCM governs how quickly the overall ignition timing can be restored to normal levels. The engine could see a peak of 15 degrees of KR from which the originating detonation may immediately disappear. However, the PCM will not instantly restore timing to pre-detonation levels. Instead, the PCM cautiously and conservatively restores ignition timing at a rate of 0.8 degrees per second. In the event of a 15 degree KR event, it would take nearly 19 seconds for the ignition timing to be restored to pre-KR levels. By the time your car sees full power again, the race is already over. This 'time' that the PCM takes to restore the ignition timing is called the Recovery Rate. The Recovery Rate will continue in this slow fashion until KR reaches zero, KR increases back above the current recovery value, or the throttle is released."

FAQ: Why is knock retard (KR) bad?

"Due to the retardation of the ignition timing, KR causes the vehicle to lose substantial power. More importantly, though, the flame front collisions are EXTREMELY harmful to the pistons. These highly volatile areas in the cylinder can cause stress cracks in your piston, which will eventually give way causing an entire CHUNK of your piston to lift right off and begin banging around inside the cylinder. This is why when the spark plug is removed after such an event, the plug end is bent all the way over. The broken piston can be VERY expensive to fix if you are not capable of doing the work yourself. DON'T EVER DISABLE YOUR KNOCK SENSORS. It takes less than 3ms to damage your engine due to knock."