Cadillac Owners Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
Owner of a 87 Eldorado HT4100, so far everything is OK no major problem. However, when she warms up I get a knocking (Rrr...rrr..rrr) sound from the engine, probably the lifters (Valve??) - no loss of power or otherwise. I guess this is the same symptom that some of our other HT4100 owner has described.

Has anyone replaced lifter or done anything to eliminate this?

Thanks
Globetrotter8888
 

·
Registered
1991 Deville / 1989 BMW 635csi
Joined
·
896 Posts
Yes it is the lifters. My 87 deville with 94,000 miles does it and my dads 87 deville with 170,000 miles does it. Run half a liter of tranny fluid in it fot 30 mins after warming up, then race it a couples times at a constant 2200rpms. They are most likely dirty, that is the reason. Then run 15w 40 oil as reccomnded by other members on this site. I still yet have to try this trick, One of my mechanics told me to do it and says it will work. DO NOT MOTOR FLUSH:tisk:!!!!!!!!!
 

·
Registered
Joined
·
28 Posts
Discussion Starter #4
Thanks for the input, the noise is pretty loud. I am planning to do a compression reading on all the cylinders, burrow a stethoscope.

Thinking of replacing the lifters if necessary or perhaps i will take caddeville suggestion first before considering the lifter replacement.

What is a great premium oil to use? I currently use Mobil 1 - 10W30.

Thanks again
Globetrotter8888
 

·
Registered
1991 Deville / 1989 BMW 635csi
Joined
·
896 Posts
As our great guru once stated, you should use rotella 15w 40 oil. Try that trick and see if it works, if not, just drive the car and don't worry about. Its just annoying as hell. If you change the lifters, i would check the cam also. If the cam is starting to wear, that knock might come back after a little while.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #6
Thanks caddeville, I will look for rotella 15W40 in my next oil change. I will probably get my lifters, rods and cams checked out this spring or sooner.

Thanks again
GT8888
 

·
Registered
1995 FWB 128,*** miles
Joined
·
2,220 Posts
caddeville said:
As our great guru once stated, you should use rotella 15w 40 oil. Try that trick and see if it works, if not, just drive the car and don't worry about. Its just annoying as hell. If you change the lifters, i would check the cam also. If the cam is starting to wear, that knock might come back after a little while.
I would first try marvel mistery oil or ATF to fix the lifters THEN use Rotella 15w-40.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #9
I have tried the Marvel Mystery Oil and it did not help. I guess I will pull the lifters and inspect the cam and see where that leads me to. The knocking sound is irritating and I am determined to get rid of it, thanks for the help will keep you posted

GT8888
 

·
Registered
Joined
·
28 Posts
Discussion Starter #10
Hi caddeville
I listened to the sound file that you posted - Thanks. Did you get rid of the knocking? Mine sounds the same it is embarassing. Marvel Mystery Oil (MMO) did not help one bit.

GT8888
 

·
Registered
1991 Deville / 1989 BMW 635csi
Joined
·
896 Posts
Did you try the tranny fluid? Half a litre and run it for 30mins HOT, then rev the hell out of it!! Mine is gone quieter, IT WAS ****IN LOUD AS HELL WHEN I GOT THE CAR!!!!! Did the noise just come up , or did it do it since u had the car? The lifter(s) is probably stuck closed due to sludge. Try more frequent oil changes. Does your engine make a slight tick also when u BARELY press the throttle?
 

·
Registered
1991 Deville / 1989 BMW 635csi
Joined
·
896 Posts
You also stated that there is no power loss, your cam is probably fine, the lifter(s) is most likely stuck closed.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #13
The car was great when I bought it, the noise sort of crept in, also I has the car in my garage for over a year drove it for a bit and then did not drive it for another year, I took it out couple of months ago. I am very thorough in the fluid maintenance of the car.

GT8888
 

·
Registered
Joined
·
15 Posts
Can Anyone Help Me,i Have A Ping In The Engine,i Use Only High Test.
I Also Tried Different Gas,went From Bp To Mobile Was Same Condition,also Tried Wot Same Condition.
No Codes Come Up On Computer.
95 Deville With 27,000 Miles.bought New.
Antony14 Thanks For Any Help......i Am New Here.
4.9L 300CID V8MFI
 

·
Registered
1995 FWB 128,*** miles
Joined
·
2,220 Posts
ANTONY14 said:
Can Anyone Help Me,i Have A Ping In The Engine,i Use Only High Test.
I Also Tried Different Gas,went From Bp To Mobile Was Same Condition,also Tried Wot Same Condition.
No Codes Come Up On Computer.
95 Deville With 27,000 Miles.bought New.
Antony14 Thanks For Any Help......i Am New Here.
4.9L 300CID V8MFI
If you hear the ping only when the engine warms up (180 plus) and predominantly at slight throttle (driving with hot engine around a block) you most likely have spark knock caused by the lack og EGR flow because of old EGR valve or plagged EGR passages.
First try to clean two EGR tubes inside throttle body (TB). Use a stiff wire to rod the cabon deposits out. Do not care of carbon falling down. Clean up th TB bores and backsides of the plates with a carb cleaner and tooth brush.

If all this does not help, replacing the EGR valve ($55) will help. To diagnose a bad valve you can connect the vacuum line from TB to EGR solenoid directly to EGR valve, thereby bypassing the solenoid. The runing engine will stall. Restart it and drive around a block when it is hot. If you cannot hear the ping, you know your EGR valve is bad. Also check all the vacuum lines from /to TB . The plastic elbows deteriorate with age. And welcome to board! EGR solenoids can fail too, but the EGR valve is the first suspect.
 

·
Registered
1995 FWB 128,*** miles
Joined
·
2,220 Posts
globetrotter8888 said:
There are two outlets from the EGR solenoid
One (upper) outlet connects to the EGR Valve
Where does the other (lower) outlet connect to?
See pictures below:
Does any one know where the lower outlet connect to???
Thanks
GT8888
I cannot see much in the pictures but an EGR solenoid must have an inlet connected with a vacuum tube to the throttle body and an outlet connected to an EGR valve.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #19
The EGR solenoid has one inlet and two outlets.
I am addressing the two outlets only. the top outlet connects to the EGR valve. Where does the second lower outlet connect to? I took two pictures to show the two outlets. When I checked around, I found this outlet with nothing connected to it, I checked the service manual and could not find any reference to it, do I just plug this outlet and see what happen, I would like to get some opinion or answers.

Thanks
GT8888
 

·
Registered
1995 FWB 128,*** miles
Joined
·
2,220 Posts
Here is how the 4.9 EGR solenoid looks like. The outlet covered with a sponge goes nowhere. I think it just sucks air when the solenoid is closed. The sponge is just a filter.
 
1 - 20 of 22 Posts
Top