Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features: Join our community! |
| Rebuild may be on the plate.; It started out as a head gasket replacement until I dug a little deeper. | |
|---|---|
| Tweet Topic Started: Aug 23 2014, 09:26 PM (534 Views) | |
| bkelly | Aug 23 2014, 09:26 PM Post #1 |
|
Gear Head
![]()
|
It's been awhile since I've posted. There's been a lot going on lately. I finally got some time to work on the car. The car is a 91 vert. I've been reading on the forum and was just going to replace the head gasket since it was blown and dropped coolant into the crankcase. Two head bolts were not completely torqued and I'm sure that contributed to the gasket failure. The more I though about it the more I wanted to pull the engine and look deeper. I just read about the pistons being numbered and the block stamped with the piston numbers. The block is stamped 221 and it has 111 pistons so I already know the motor has been worked on. That makes me uncertain, I have a hard time trusting other peoples work if I don't know who done it, so I decided to pull it. I get the motor out and find it has a 5 bolt crank pulley. I assume they previous owner either swapped pulleys or a newer motor. The previous owner did spend some time and money on the car. When I was pulling the axles to pull the engine and transmission that I noticed it had new breaks, rotors, axels, and lower control arms. Also inspected the horns and they are solid. The car also has a new convertible top, swift tail lights, new exhaust, wheels and tires. I'm guessing they spent all the time and money and the head gasket blew after it was just replaced and decided they had spent enough on the car. I ran out of daylight so all I got done was pull the engine and transmission. I will get the oil pan off soon and see how the bottom end looks. Pull a main cap and inspect the bearing and journal. The cylinder still has cross hatch from being honed so I assume it has new rings. I'll post some pics when I get time to get them hosted. |
![]() |
|
| bkelly | Aug 23 2014, 09:34 PM Post #2 |
|
Gear Head
![]()
|
![]() You can see the #2 piston is clean from the blown head gasket.
Edited by bkelly, Aug 23 2014, 09:54 PM.
|
![]() |
|
| freegeo | Aug 24 2014, 12:37 AM Post #3 |
![]()
|
Those numbers are stamped in at the factory. After market pistons would have just an arrow and probably a number if it was bored over any. If you can still see cross hatch that could be a good sign it isn't worn much. You need to measure the bores according to the FSM to make sure. |
![]() |
|
| bkelly | Aug 24 2014, 10:08 AM Post #4 |
|
Gear Head
![]()
|
The pistons look like factory pistons. They have a arrow and the number on the top of the piston. The factory stamp is 221, the pistons are all 1 pistons. ![]() I assume they had to replace the pistons and used factory pistons from another motor. I'll have to take it to a shop to have the bore checked. All I have is calipers. This does have me concerned though. It looks like erosion between the sleeve and block on #2 and some strange markings on the cylinder wall of #2 ![]() ![]() Edited by bkelly, Aug 24 2014, 11:01 AM.
|
![]() |
|
| freegeo | Aug 24 2014, 10:51 AM Post #5 |
![]()
|
See if there is a FSM available in the factory repair manual section. I looked but didn't see one for a 91. Post and see if someone here has one and can look the info up for you. Before putting it back together make sure the top of the block and head surfaces get checked for flatness. Head surface is .002" for flatness according to my 97 FSM. Might be different for yours but a good place to start . I would think the block would be the same for flatness. The # 1 on the block indicates the cylinder bore size to be between 2.9138" - 2.9142" The # 2 on the block indicates the cylinder bore size to be between 2.9134" - 2.9138" The # 1 on the piston indicates that the piston diameter is 2.9126" - 2.9130" The above numbers came from a 97 FSM and may be different for a 91. Please verify those numbers to be correct for you. Have you had the car very long? |
![]() |
|
| freegeo | Aug 24 2014, 10:56 AM Post #6 |
![]()
|
Have you checked the number stamped into the block to see if it is a engine from a different year? Numbers should be near the trans area and start with a letter. That letter should be the 10 digit of the vin. If they match then it should be a 91. |
![]() |
|
| bkelly | Aug 24 2014, 11:09 AM Post #7 |
|
Gear Head
![]()
|
I'll have to check the numbers on the block for the year. I bought the car for $800 off craigslist with the engine in this shape. I knew it was running but had a blown gasket so I trailered it home. I checked the compression and all three were in the 155 range. |
![]() |
|
| perfesser | Aug 24 2014, 10:24 PM Post #8 |
|
Elite Member - Former Metro owner
![]()
|
You might find the build log from my '91 interesting. I had a head gasket failure and was just going to replace the gasket, but got carried away. My cylinders had decent cross-hatching visible but were worn past the limits, so I went 0.020" oversize. And on, and on, and so forth, etc., etc. Runs great now, though! Be sure to start a project thread when you get started and remember - pics or it never happened!! ![]() The engine number is on the parting line between the engine and transmission, below the large 993 CC that's cast into the block. "M" would indicate a '91 block, but really won't tell you a thing about any other component in it. For example, my engine has the original crank and rods in the block, and everything else is new or refurbished from a different engine, from the oil pump to the oil filler cap! Edited by perfesser, Aug 24 2014, 10:28 PM.
|
![]() |
|
| Woodie | Aug 25 2014, 05:24 AM Post #9 |
![]()
|
Get some 40 over pistons and have your machine shop bore/hone to match. That way the numbers won't matter and the marks on the cylinder walls will be gone. |
![]() |
|
| perfesser | Aug 25 2014, 09:37 AM Post #10 |
|
Elite Member - Former Metro owner
![]()
|
FTFY |
![]() |
|
| bkelly | Aug 25 2014, 10:49 AM Post #11 |
|
Gear Head
![]()
|
Does anyone have info on DNJ parts. I've never used them so I would like some reviews from people with firsthand knowledge. I was looking at the parts on Rockauto. The CFO approved the topend rebuild and sending the head to the shop to cut new seats. I ordered a Felpro head gasket set, water pump, thermostat, head bolts, timing belt set, and new valves. The parts should start showing up this week. I also see where some people are reusing the bearings for the rods and mains, is this common with these engines? I’ve always replaced bearings but if it’s been tried and proven I will follow your direction. I understand these engines wear out the top end before the bottom but I don’t know the builder history on this engine. I hope that I will have time today to get the engine on the stand and look at the bearings. I know I need to get the pistons before I take the block to the machinist to have the bores cut. If it needed bearings, I wanted to have them on hand as well. Does someone have the specs for the oil pump? I was thinking about reusing it, my experience on some other motors is the pumps hold up well. |
![]() |
|
| perfesser | Aug 25 2014, 12:33 PM Post #12 |
|
Elite Member - Former Metro owner
![]()
|
IF the bearings and journals mike out within limits, you can reuse the bearings. I did on my '91 based on the advice of the gurus here. I'd always replaced with new, too, and was a bit hesitant about reusing them, but it runs like a new engine. |
![]() |
|
| bkelly | Aug 25 2014, 09:18 PM Post #13 |
|
Gear Head
![]()
|
Well it looks as if it is a 91 block. I had to scrape a 1/8" of oil and dirt away to find it. l
|
![]() |
|
| perfesser | Aug 25 2014, 10:14 PM Post #14 |
|
Elite Member - Former Metro owner
![]()
|
Yeah, I felt like an archaeologist excavating down to my number, too!! |
![]() |
|
| 1 user reading this topic (1 Guest and 0 Anonymous) | |
| « Previous Topic · Engine Tech & Diagnostics · Next Topic » |


Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.











3:48 AM Jul 11