2001 V70 t5 surging +other issues[cheap cl buy]

Redmerlebaby · Post by **Redmerlebaby** » 23 May 2025, 10:18

Tldr: engine surging on idle and hissing near intake manifold
Any ideas for temporary way to improve pcv function

Codes:
P0128
P0101
P1332
P0447

So I went and bought this car off cl for $600. It's in decent shape I think, aside from some engine issue and common front end stuff. 179xxx mi
Engine problem is seemingly airflow.
Tested for vacuum leaks with carb cleaner method, but no reactions (also blew it through the MAF housing). Right now I'm thinking PCV Valve and I've got on order, but curious if anyone knows any additives that would help temporarily while I'm waiting.
Car surges in idle, particularly when hot. In the morning first thing it's very mild. All Lights also surge with the engine. Hisses near exhaust manifold (also follows surge timing). Surging is very consistent in timing.
Also interested in any other suggestions of issues/resolvements. I believe the last scheduled maintenance benchmark reached was transmission at 147xxx, and the 3 owners after I am unsure if they did anything (including oil change)

Vova585 · Post by **Vova585** » 23 May 2025, 11:30

Please look up videos "volvo glove test". This year volvo utilizes convoluted pcv greather box with hoses that is usually lasting 10 years/100k and needs to be changed. Not very complicated job, but please only use original hoses.
I would invest Into smog tester and see what exactly is "hissing"

Redmerlebaby · Post by **Redmerlebaby** » 23 May 2025, 20:17

I saw on this forum a guy using 5/8" heater hose for one of the pipes (not the one that feeds out above the intake manifold).
He was saying as the engine gets higher mileage the stock sizing can cause smoking from dip and clogs more easily I think. Any opinions on this?
viewtopic.php?t=53448

Vova585 · Post by **Vova585** » 23 May 2025, 20:50

IMHO: decide if you like this car and if you are willing to invest your time and great deal of money into it. If it was not pampered by last owner-you inherited all the aging issues and lack of maintenance. If you are not ready-run away it is expensive old car that will need around 2-3k in maintenance to be able to drive another 70-100k without much problems.
Back to your car: start with replacing air filter and properly cleaning maf(one of the codes), looks like your thermostat is also needs to be replaced($30 for part, I would hold on coolant flush until your sort rest of the issues), figure what is hissing? Is it a vacuum leak(most likely since your maf is likely throwing the code because if it)? Get yourself a smoke tester(vtl member suggested recently great option for about $80) and check what is in need to be adressed(likely turbo control lines(ipd sells silicone ones) but could be as simple as badly seated intake hose at throtle or at Intercooler. You will save yourself money and time with smoke tester. Test pcv system via "glove test" and if failed- time to put normal parts and clean all passages in extreme cases to drop the oil pan.
My 01 has 300+ miles on the engine and there is no need for any improvements in in pcv hoses. If your piston rings are shot, than no matter the size of the hose it will not work. This cars like timely maintenance and oem parts. Please dont use aftermarket rubber components or electronics(OEM or OE or used oem) and you will be happy in a long run. After all tune ups you will have a great and reliable car for years to come. Average monthly payment is about 700-800 now? So for equivalent of 4 monthly payments you can have a good car, but it will not be cheap or easy(here all audi and BMW friends will offer us to hold their beer)

Post by **jonesg** » 24 May 2025, 07:33

Redmerlebaby wrote: ↑23 May 2025, 10:18 Tldr: engine surging on idle and hissing near intake manifold
Any ideas for temporary way to improve pcv function

Codes:
P0128
P0101
P1332
P0447

So I went and bought this car off cl for $600. It's in decent shape I think, aside from some engine issue and common front end stuff. 179xxx mi
Engine problem is seemingly airflow.
Tested for vacuum leaks with carb cleaner method, but no reactions (also blew it through the MAF housing). Right now I'm thinking PCV Valve and I've got on order, but curious if anyone knows any additives that would help temporarily while I'm waiting.
Car surges in idle, particularly when hot. In the morning first thing it's very mild. All Lights also surge with the engine. Hisses near exhaust manifold (also follows surge timing). Surging is very consistent in timing.
Also interested in any other suggestions of issues/resolvements. I believe the last scheduled maintenance benchmark reached was transmission at 147xxx, and the 3 owners after I am unsure if they did anything (including oil change)

Could be a very nice buy...

put a voltmeter on the battery and monitor v as you change engine speeds, it should stay mostly stable, if not , I would swap out the voltage regulator on the alternator, $50. OEM parts only, no ebay parts.

hissing around the exh manifold is can be the rubber charge air coupler sleeve from the turbo to the big plastic charge air pipe that goes over the engine, make sure its not ripped and is clamped firmly. $60. Inspect the big plastic air pipe for cracks underneath.

Read coolant temp with your code reader. If its running cold, below 160F, it will not run well like that.
If you swap out the temp coolant sensor avoid aft mkt parts, they will not work.

Glove test it, if it inflates the glove loosen the dipstick to relieve pressure or risk blowing out the cam seals.
If you end up doing the PCV system, get OEM parts from FCP, do the voltage regulator if needed whilst its exposed, the thermostat will be easy ro swap out at the same time too.

A quality scanner or VIDA if you keep the car, I would.

A CVVT code was fixed on mine by changing the oil and filter.

Redmerlebaby · Post by **Redmerlebaby** » 06 Jun 2025, 22:43

A little update: redid PCV(lines and oil catch). Haven't done banjo bolts.
Currently the codes are now evap, vvt, and cam position.
Oil pressure sensor is leaking, and I'm suspecting that's the vvt code source. Thinking purge valve is my vacuum leak, and may indirectly be creating the poor conditions to make can position sensor code trigger. Any thoughts?

Redmerlebaby · Post by **Redmerlebaby** » 06 Jun 2025, 22:46

Also after I fixed a major vacuum at the PTC on the air intake hose it started making this noise that sounds kind of like a deep low boing sound. Not making it now, but thought that could possibly be something indicating an issue. For those who may have played legend of Zelda ocarina of time the noise is kind of similar to a Goron. Like maybe how I would imagine them gulping would sound.

Post by **jonesg** » 07 Jun 2025, 02:52

low oil pressure can cause vvt and can problems.
Vida has a reaction test for the vvt.