98 B5254T head on 99 block?

Gtin · Post by **Gtin** » 05 Oct 2022, 20:00

Summary: can I replace my 98 B5254T with a 99 B5254T, assuming I use the head, cams, etc from the 98?

Hey guys, been a few years since I posted. I've had a 98 v70xc sitting around for a good while now in storage while weeks turned into months turned into years until I finally decided enough was enough, let's make it run.

A little long-winded backstory, so strap in.

previously I had tried to hack the head gasket and poured a bottle of sealant in it, as it's worked for me in the past. No such luck, and for anybody curious, I've supported this stuff before, and I redact all of that, coolant passages on this thing are filled with it.

Anyway, Confirmed the bad head gasket with a block test and thought I could get it home to strip down, no luck, several exhaust valves burned out a couple miles down the road. Towed Back to the storage lot with no Compression I decided to tear it apart there, it was dark when I got the head off and I decided inspecting the cylinder walls could happen next week while the machine shop looked over my head. Machine shop said they'd get back to me in a week to let me know if it could be salvaged, so I figured I had plenty of time to go check the rest of this engine out. They called the next day to let me know they could fix it, for $570. That's cleaning, testing, resurfacing, replacing 5 exhaust valves, the rest of the valves were usable. So I pulled the trigger, they set to work and I ordered the gasket kit, bolts, timing belt kit with water pump, serpentine belt, PCV kit, thermostat, basically I'm like $900 deep in this thing

Anyway, here's the rub, I got the head back and took it out to the car today, finally got to look at the thing, and realized how Big of a mistake I made approving that work. I've got significant damage to at least 3 cylinder walls and 1 piston. My first thought was to pull it, hone it, sleeve it, replace any bad pistons and bearings, go about my day, would give me a chance to reseal the entire engine anyway, which it needs. As it turns out, I can't find cylinder sleeves for this thing, it looks like it's sleeved from the factory, and I was hoping to get away with standard replacement parts if the cylinder walls looked ok when they were removed, but I can't find standard or oversized kits for it.

So in searching I found that used engine prices have sky-rocketed for these cars, but what I did find was a decent looking 99 xc with (allegedly) a cracked head for a good price. I'm under the assumption that putting my head on that car is a no-go on account of the VVT, but what Im curious about is are the blocks the same? I know they upgraded the engine management in 99 with the VVT, but would everything from my 98 bolt up? So I could pull that engine, swap my head onto it, and drop it into my 98? Or would my ECU plug and play in the 99? I could just do the head job and swap in the 98's ECU to have a 99 with no VVT?

Post by **scot850** » 05 Oct 2022, 20:30

I know a friend of mine had a 98 V70 AWD and fitted an engine from a 2006? S60 and if I recall removed the VVT and used the 98 ECU. The issue I would see is that the 98 were mostly fitted with the hydraulic tensioner, but then some were fitted with the manual tensioner too.

One bonus is that you would have the later pancake oil cooler on the oil pan and could do away with the engine oil cooler thermostat and pipes!

Hopefully some of those who have done swaps will pitch in.

Neil.

Gtin · Post by **Gtin** » 05 Oct 2022, 20:42

scot850 wrote: ↑05 Oct 2022, 20:30 I know a friend of mine had a 98 V70 AWD and fitted an engine from a 2006? S60 and if I recall removed the VVT and used the 98 ECU. The issue I would see is that the 98 were mostly fitted with the hydraulic tensioner, but then some were fitted with the manual tensioner too.

Hopefully some of those who have done swaps will pitch in.

Neil.

Mine is a manual tensioner, so I'm covered on that front. Thank you for the input! It also just occurred to me that I'm going to have to have an emissions test to get this thing legal, and if I enter the VIN for the 99 but the ECU reads 98 it's not only going to fail emissions, I'm probably gonna get a fun little visit from highway patrol thinking that I'm trying to fool the system by plugging in a different car. So swapping my head and ECU into the 99 is officially a no-go.

Post by **Chuck W** » 06 Oct 2022, 09:56

You wouldn't be able to use the M4.4 ECU from the '98 in the ME7 '99 anyway. Harnesses are totally different.

You could use the block from the '99 in your '98 though, and use your '98 head (Not sure which head gasket you'd need to use though). You'd gain the stronger RN block and the benefits of the RN oil cooler set-up.

(What color is that '99 XC70, BTW?)

Gtin · Post by **Gtin** » 06 Oct 2022, 10:49

Chuck W wrote: ↑06 Oct 2022, 09:56 You wouldn't be able to use the M4.4 ECU from the '98 in the ME7 '99 anyway. Harnesses are totally different.

You could use the block from the '99 in your '98 though, and use your '98 head (Not sure which head gasket you'd need to use though). You'd gain the stronger RN block and the benefits of the RN oil cooler set-up.

(What color is that '99 XC70, BTW?)

Good info, my lead tech at work wants me to pull the engine and bring it in for him to look at first, he believes it can be repaired. So im gonna bring it in and let him get measurements on the damage and go from there. which is just as well because the 99 isn't replying to my messages, it's silver.