Loud Lifter Knock/Missing coolant/Intake Manifold Gasket

[Rick Norwood]

I decided to start my own thread on this issue rather than hose up someone else's thread.

2000 GMC Jimmy 4.3. 61,000 miles. Just started with a loud lifter knock over the weekend. Oil and coolant change less than 1000 miles ago. I checked the under side of the oil filler cap and saw what I thought was a lot of moisture. The oil does not appear to muddy. However it does appear to be slightly more full than I remember filling it at the last oil change. The coolant in the plastic reservoir tank is also a little lower, but that could be from working the air out of the system from the last flush.

I immediately started to suspect the intake manifold gasket. Does anyone have a service bulletin number on this? Is there a good test to prove if it is the Intake Manifold gasket or not?

I'm still under an extended warranty and I don't want a run around at the Stealership when I take it in. I'm sure they're going to tell me something like I need an Oil additive to quiet the lifters or Aluma-seal for the Radiator.

Any Help or similar experiences would be greatly appreciated.

[Rick Norwood]

Sorry, there is a slight typo in my first thread. The Oil does not appear to BE muddy at all. It is a golden honey brown color.

Is there a test to see if there is coolant in the oil?

[mars-28]

I saw your thread and decided to cut and paste my reply to an earlier thread I replied to. I hope you don't have the same problem.

I have a 99 Jimmy with 106,000 miles. I kept up with oil change every 2-3000 miles, flushed the coolant system a number of times. Just before Christmas I was having trouble with no heat and engine overheating. After the heating problem was fixed the motor developed a tick or knock to it. Apparently with the intake leaking coolant it was also leaking internally and was not visible during oil changes. Basically the motor is junk. Rebulding what I had was just as expensive and the warranty didn't compare to what I could get from Jasper.

[BlazerLT]

Rick, what oil filter are you using?

What grade of oil?

Have you ever done an engine flush?

[Rick Norwood]

Originally Posted by BlazerLT

Rick, what oil filter are you using?

What grade of oil?

Have you ever done an engine flush?

I normally use the AC Delco PF52 filter, however the last two oil changes my local Autozone was out of them, so I bought the STP Brand for this engine. (The only other choice was FRAM, which is a big NO-NO.) I used Castrol GTX 10W-30. (All of the local parts stores and even the Stealerships tell you to use 10W-30 oil here in the Phoenix area. very few of them even carry 5W-30.)

I bought this Truck 1½ years ago and it had 30,000 miles on it and have never done an engine/crankcase flush.

I stopped at My local Autozone and picked up a new Oil change last night on my way home from work and bought Castrol 5W-30 and another STP filter (they're STILL out of AC Delco!). I am going to make an appointment with the Stealer today and will probably have to leave the truck with them overnight so they can hear the noise in the morning upon cold start-up.

I am afraid if I do a crankcase flush or go to the 5W-30 oil, I might mask an even bigger problem, as I do know three things:

1, I have a very loud lifter noise on cold start-up (that just started Sunday morning) that goes away after 2-3 minutes.

2, I seem to be using a little coolant (approx. 1 quart in 1000 miles since my flush in January).

3, There was moisture in the oil filler cap when I checked it yesterday. I wiped the moisture out of the cap and filler neck and will check it again today.

As I stated earlier, I have an extended warranty on this truck and don't want to risk screwing that up. If it is the intake manifold gasket or some other major issue, I don't want to find out after the warranty is over.

Just for the record, what brand of crankcase flush do you recommend?

[keeley120]

well, i have a 95 gmc jimmy, that has had buckoos of mechanics look at it, and have put alot of money it...anybody know what would make the truck idle badly...even though after it's run awhile...it seems to be fine? also...there is an overpowering gas fume the whole time it's running...and black watery soot comes from the tailpipe...it has no scent...but literally will coat the ground instantly upon a cold start-up...sorry about my lack of knowledge...i'm a nursing student...who has time for mechanics class too? lol...Kelly

[Rick Norwood]

Originally Posted by keeley120

well, i have a 95 gmc jimmy, that has had buckoos of mechanics look at it, and have put alot of money it...anybody know what would make the truck idle badly...even though after it's run awhile...it seems to be fine? also...there is an overpowering gas fume the whole time it's running...and black watery soot comes from the tailpipe...it has no scent...but literally will coat the ground instantly upon a cold start-up...sorry about my lack of knowledge...i'm a nursing student...who has time for mechanics class too? lol...Kelly

You might want to start your own thread on this problem, however, please give us more information. Where do you smell the gasoline odor? Inside the truck? in the engine compartment? At the exhaust pipe? Have any of these "Mechanics" ever done a basic Tune-up, Plugs wires etc. Have you ever seen your "Check Engine" Light light up on the dashboard? It almost sounds like you're running too rich and I would suspect the Oxygen sensors, however, please respond back with more information so we can try to help you.

Rick

[keeley120]

Originally Posted by Rick Norwood

You might want to start your own thread on this problem, however, please give us more information. Where do you smell the gasoline odor? Inside the truck? in the engine compartment? At the exhaust pipe? Have any of these "Mechanics" ever done a basic Tune-up, Plugs wires etc. Have you ever seen your "Check Engine" Light light up on the dashboard? It almost sounds like you're running too rich and I would suspect the Oxygen sensors, however, please respond back with more information so we can try to help you.

Rick

hello Rick, sorry about screwing up my first msg here...i smell the gasoline odor in the truck...as well as outside...has had a complete tune-up...one oxygen sensor was supposed to have been put on last year...but whether it really was or not, i don't know. check engine light stays on mostly...one mechanic told me the soot was because it was flooding so bad...too much gas coming through...but he had no suggestions....about 6 months ago i had a mechanic look at it because it would just die if u came to a stop...anywhere. He put a screen over something...ran great..for about 24 hrs., then the same thing. I just put a new controle module in it for my 4wd...as well as oil change, heater coil(this makes the 2nd one), and flushing the radiator. I also had a cadilic convertor put on...and some kinda valve that has a pin that is supposed to pop in and out...but mine was stuck...when i start it, gas fumes are really strong, and it idles like it wants to quit, then idles higher, then almost dies again...hope this helps...ty Kelly

[Rick Norwood]

You have multiple issues here. Go to Autozone and have them read the codes for you. Write the actual code numbers down and come back and post them here. The EGR Valve is probably bad among other things. These "mechanics" that you refer to are not. Stay away from these guys and stay away from the dealerships unless you have a alot of money.

[BlazerLT]

Originally Posted by Rick Norwood

I normally use the AC Delco PF52 filter, however the last two oil changes my local Autozone was out of them, so I bought the STP Brand for this engine. (The only other choice was FRAM, which is a big NO-NO.) I used Castrol GTX 10W-30. (All of the local parts stores and even the Stealerships tell you to use 10W-30 oil here in the Phoenix area. very few of them even carry 5W-30.)

I bought this Truck 1½ years ago and it had 30,000 miles on it and have never done an engine/crankcase flush.

I stopped at My local Autozone and picked up a new Oil change last night on my way home from work and bought Castrol 5W-30 and another STP filter (they're STILL out of AC Delco!). I am going to make an appointment with the Stealer today and will probably have to leave the truck with them overnight so they can hear the noise in the morning upon cold start-up.

I am afraid if I do a crankcase flush or go to the 5W-30 oil, I might mask an even bigger problem, as I do know three things:

1, I have a very loud lifter noise on cold start-up (that just started Sunday morning) that goes away after 2-3 minutes.

2, I seem to be using a little coolant (approx. 1 quart in 1000 miles since my flush in January).

3, There was moisture in the oil filler cap when I checked it yesterday. I wiped the moisture out of the cap and filler neck and will check it again today.

As I stated earlier, I have an extended warranty on this truck and don't want to risk screwing that up. If it is the intake manifold gasket or some other major issue, I don't want to find out after the warranty is over.

Just for the record, what brand of crankcase flush do you recommend?

The coolant you are losing is actually probably the air pockets in the system being displaced.

Yea, I recommend an engine flush if you are not leaking oil. Just add a bottle of engine flush to a warm engine and allow it to idle for 30-40 minutes to dissolve out the crud and sludge in the engine. Remember, ONLY IDLE. Also, I recommend swapping on a cheap fram filter while you are doing the flush so it catches all the gunk coming out of the engine. The filter will be plugged in 30-40 minutes so it is best to have a fresh filter on there while doing it. Then drop the oil and the cheap filter and install your new oil and a good non-fram filter. Also note, to get all of the flush out, I recommend pouring a bit of fresh oil in while the drain plug is out to get all of the old oil out of the pan.

Now if you are me and you want to do a really GOOD FLUSH, drop the old oil before you do the flush and add 3 quarts of some bargain basement 10w30 in with the engine flush and the cheap filter so you get the best flush possible. Remember, you are only doing this once, so the extra $10 will go a long way. You will be amazing how dirty the new oil comes out with the flush. Then drain, and add the new filter and the new 5w30 oil with a little new oil in through the fill so you can get it all out of the pan like I stated earlier.

The knock at startup is usually a oil problem.

Also, moisture under the oil fill cap is normal.

[Rick Norwood]

Come to think of it, The STP number is the same as the FRAM number. (Oh $hit$ki) What brand (if any) engine cleaner do you suggest? Please don't tell me Seafoam! (LOL)

[BlazerLT]

The Gunk brand I had a great experience with.

Follow the instructions above.

[Rick Norwood]

Originally Posted by BlazerLT

The Gunk brand I had a great experience with.

Follow the instructions above.

Thanks Man, I 'll get some on the way home! Thanks for turning the light on about the STP Filters. You ought to run that website again for all those that missed it the first time.

[BlazerLT]

Remeber to buy two filters.

One junk fram for the flush and a good filter for the new fill.

Remember to run a little oil down into the crankcase to get rid of all the excess oil with the flush.

[Rick Norwood]

Just because I'm old and dense:

Should I add the quart of cleaner to cheap oil and junk filter after I drain the existing oil out, and then start the engine,

or

Should I add the 3 quarts of cheap oil, junk filter, warm up the engine, and then add the cleaner?