Piston rings? Head gasket?

Khorn09 · Post by **Khorn09** » 26 Mar 2019, 15:36

Hey guys! I'm new to the site and i figured I'd come by there and ask for your viewpoint. I recently picked up an 03' XC90 AWD with the 2.5L. Owner said it needed a radiator. I fixed that. Now I'm trying to start it and had a little luck after I tried a few things. I checked the fuel pressure, it's reading 45+. Checked spark, and changed plugs; i'm good there. Then i did a compression test and got some weird readings. 40-90 psi all around. weird. Thought my guage was broken, so i put some oil in the cylinders, and compression jumped to 90-120's between the cylinders. still weird, pretty low i think. Put it all back together and it actually started. After about 20 seconds it just straight out died again. Wouldn't start. Is it common for the 2.5l to have severely worn out rings at 140k miles? could it be broken rings? Maybe it overheated, and cracked a ring or something? I'm just trying to figure out my next plan of action here. I mean, i could re-ring it but i'm looking to see what you guys have to say first. Totally new to volvo's.

Post by **June** » 26 Mar 2019, 17:22

These engines are prone to lawnmower syndrome. If you can get it to start then get the rpms high until it clears up. It would be unlikely a head gasket would effect all 5 cylinders. And from what I've experienced the rings are robust. It's the valves that cause compression trouble. My last 5 cylinder was prone to hard starts every so often and the dealer advised to drive it down the interstate at 5000rpm for 5 minutes. It would clear it up for a while. Engine must be under load.

I have done that with every Volvo since every 6 months. My current car has 178K and 15 years in service now. I always shut AC off and do it with a fresh oil change. June

tardcart · Post by **tardcart** » 26 Mar 2019, 18:18

the radiator is a hint that it overheated/head gasket. also this is why it was for sale. However it is possible that the timing jumped two or three teeth. that would give uniform low pressure on every cylinder. pop the top cover and turn the pass tire all the way to the right and put a socket on the crank and turn it clockwise till the cams line up on the top marks. then see if the crank balancer mark is directly below the front timing belt.

tardcart · Post by **tardcart** » 26 Mar 2019, 18:23

another remote possibility for low compression (besides your tester) is a completely blocked exhaust/cat. that would explain starting and then stopping after a Minute. If it had been sitting a mouse could have nested in the muffler. did it seem way too quiet?

Khorn09 · Post by **Khorn09** » 26 Mar 2019, 19:03

thanks for the info guys, i'm gonna pull the plugs again and throw some more oil in there to get it started, then just stand on the accellerator for a few seconds. see if i can get to idle before i take off. either way, if these engines do have lawnmower syndrome i'm gonna have to put oil in there anyways. I just hope to god it didn't overheat so bad the rings became unsprung or broke. I didn't hear anything knocking when i got it running for those few seconds. crossing my fingers and hoping for the best. i'm not afraid of doing a headgasket, i just don't want to have to rering it. is it possible to get the pan off while it's in the car? so if i do have to go that far i can re ring it in the car? I've done dingle ball hones and re-rings with the engine in the car before with pretty good results.

Post by **oragex** » 26 Mar 2019, 21:04

Also read a little about FPS an PEM
What was wrong with the radiator ?

Khorn09 · Post by **Khorn09** » 29 Mar 2019, 14:46

well as it turns out it is a headgasket. Blown pretty bad too it seems. Anyways, after i cranked on it a while, i noticed i was leaking coolant again. Naturally, i was thinking "Oh god now what?" So i took the reservior cap off and cranked it, it then gushed fluid all over the place. So it's getting pressurized. On top of that, the distilled water smelled like gas. so i put a lighter up to the reservoir to confirm my suspicions; and singed some hand hair off a split second later. Anyways, thank you guys for the input thus far! Next week, i'll be ripping the head off of it!

Post by **abscate** » 31 Mar 2019, 08:30

Use Volvo OEM parts only, especially on gaskets. The cheap ones are a siren song to be re-doing the job in 6 months. People will tell you XXX "makes these for Volvo" which may/might/could be true and is tested by the six month interval of failure when you find out this wasn't true.

This is a clear 'cry once' job - buy the best parts you can.

Post by **kallekula** » 31 Mar 2019, 11:52

abscate wrote: ↑31 Mar 2019, 08:30 Use Volvo OEM parts only, especially on gaskets. The cheap ones are a siren song to be re-doing the job in 6 months. People will tell you XXX "makes these for Volvo" which may/might/could be true and is tested by the six month interval of failure when you find out this wasn't true.

This is a clear 'cry once' job - buy the best parts you can.

Where do u get this info from? I’ve had a Reinz head gasket on my S70 that has been working fine for seven years now. What brands should one avoid if that is the case. Volvo here charges around $140, which is absolutely ridiculous.

Post by **Roger_850T** » 03 Apr 2019, 18:15

I go back and forth on which brands to buy. I've bought reported OEM brands, and sometimes they are excellent (Bosch), and sometimes they are not. For suspension parts, I have been burned too many times, and I only by Volvo. Especially control arms. For gaskets, it's a tough call. I just did a bunch of work on my V8, and used only Volvo parts and gaskets for everything. I don't want to have to do all that a second time.

From the low compression on all cylinders, the timing sounds definitely in question, that's the first place I would look. When you reassemble after the head gasket, I recommend you be exceedingly meticulous about making sure the cams are set properly. Especially with the VVT hubs.