88 Reliant 2.5 Loud Knocking Noise

[CTemple]

Hi guys! I'm new to this forum. I've ran into a problem with my 88 Reliant and have been looking all over for an answer or some guidance in the right direction. My problem is a knocking noise coming from the engine. With that being said, trying to find any info is futile since the knocking noise is shrugged off. Mine is bad.

Car has 154K miles on it. Just did an oil change.

Here is what happened:

I was going around 75 on the interstate. The noise of the engine became very loud, but nothing outside the loudness was odd, meaning the engine made no "new" noises. I let up off the accelerator to see if the noise would change, which it did. Then, testing what was going on, I gave it some gas. The car refused to accelerate and the loud noise came back. My temperature gauge skyrocketed to hot, oil light came on, and a small amount of smoke began to pour from the the hood. I pulled over. After letting it sit for about 4 hours, (I was on my way to work. Wouldn't start back up.) my dad was able to get the car moving, but only took it about 1/2 mile because he didn't want to push it. To end the story, car was towed to my house and I've been working on it since.

When it was fired up last, the engine sounded fine. Idling sounded good. However, when a load was put on the motor, a loud knocking noise is heard from the engine. That is of now.

I have pulled off the valve cover and checked the rocker arms and lifters. None feel loose. Running the engine for a few seconds with the valve cover off didn't show any signs of bad lifters or rocker arms. The moved smoothly. Now, I've pulled off the oil pan due to another idea given to me. The armatures that attach the piston to the crankshaft feel pretty loose on two of my pistons. Another one has a loose feel, but nothing like the first two. The two mention before can make a clanking noise by my movement. I have looked in a repair manual, and it looks like it calls for the engine to be lifted.

My question is if anyone else has experienced this, and what they did to fix their car if possible, or if anyone has any ideas that they can give me to check.

[K-CAR_WAGON]

I have not had that noise on my K-car. However, loud knocking noises are sometimes do to bad engine bearings (particularly a bad connecting rod bearing). Piston wrist pin noise can also make noise but generally get worse gradually. Loss of oil pressure is very bad and continuing to run with no oil pressure can do alot of destruction to the engine.

[CTemple]

Bearings feel tight. My dad talked to a mechanic about it and was told that the piston and piston armatures shouldn't be moving. They indicate either the piston is worn/broken or they are loose and a torch wrench should be used to make sure they are up to specs. The car was only ran maybe 2 miles after it initially started acting up. The car is parked in a garage, valve cover off and oil pan dropped. Hopefully I can save it.

[K-CAR_WAGON]

Are you saying that the lower end of the connecting rod is tight with respect to the crankshaft, but that the piston moves alot at the top end of the connecting rod where it attaches to the connecting rod through a wrist pin (indicating a broke piston)? There is typically no bolt at the top end of the connecting rod to torque where the connecting rod attaches to the piston (as far a I know). The connecting rod cap bolts are torqued at the lower end. Anyway good luck.

[88AriesLEwagon]

I'm wondering if the balance shafts are going out.They have pressure lubrication going to them.

[CTemple]

No. The armature is loose in respect to the crankshaft. So, loose piston, or broken piston as far as I'm hearing about it.

[88 aries]

what happens on these 2.5's is when the balance shafts wear out the engine looses oil pressure, this sounds like the exact same case as my 1988 had when she was 14 years young. your motor sounds like it lost oil pressure, and damaged the lower end, if the knock is louder than average, and when i mean average I mean the wrist pin knock that these motors are known for. if you do need another engine I would swap in a 2.2, as much as I like my 2.5, they are tempermental when they age.

[89ARIES]

Guess my 2.5 find be turning into a POS. I'm sorry to hear that. My car just did an automatic shutdown for fun last night. Don't despair though, We will try to get your car right. Nature of the beast. I am starting to realize the 2.2 is probably the superior engine.

[88AriesLEwagon]

2.2 all the way baby.

The less moving parts,the shorter the stroke,the better.
I dont consider the few extra hp worth it for the additional .3 liters displacement.
Sure,torque is a reasonable boost,but if you have an automatic (the torque converter multiplication until stall speed),and especially a wagon (3.08 gearing) the 2.2 is not that bad.

[89ARIES]

My 2.5 is still going strong at 170,000, and has that wrist pin slap you mention, but is not reliable if that shutdown problem is not fixed. The 170,000 are original. But, now you got me
thinking about a need for balance shafts and stuff, or maybe just selling my car buying a 2.2 K-car. Well, if the glich can be fixed, I will keep my car and aim at replacing the balance shafts at 200,000, assuming
the car makes it. Its not losing much oil and gas mileage was still good. I hear the longer stroke 2.5 usually prevents car from making 100mph, and that the 2.2 can make 108mph. So, man, I didn't want to start bashing the 2.2, after many here bashed the 2.6 and scared members, but I always thought 2.5 was superior. Now I am not so sure. The wrist pin slap has never gotten worse in my 7 years and 120,000 miles of driving since I got this electrical gremlin coupe.